Classification of Mining Systems for Ore Deposits

G. E. Bakanov

Acting professor, Candidate of Technical Sciences

1. The Significance of a Scientifically Substantiated Classification of Mining Systems

I. V. Stalin, in his speech at the conference of Marxist agrarians (27.12.1929), speaking of the significance of theory, said: “... It is known that theory, if it is truly theory, gives practitioners the power of orientation, clarity of perspective, confidence in work, and faith in the victory of our cause” (1, p. 442).

This statement by I. V. Stalin shows what great significance he attaches to theory and what requirements must be imposed upon it in order for it to be truly the theory of one or another branch of knowledge.

The classification of mining systems for a characteristic category of mineral deposits is a generalization of experience, a theoretical foundation in the field of knowledge concerning their extraction. Consequently, a properly constructed and scientifically substantiated classification of methods of mining, let us say, ore deposits, is of enormous significance for the mining industry. First, it must serve as the basis for establishing a unified, entirely intelligible, and generally accepted terminology for mining systems; and second, most importantly, it must help practitioners correctly solve questions of the selection of mining systems for the specific conditions of work in production. At the same time, such a classification must facilitate control over the correctness of the mining of ore deposits, which are of enormous significance for our socialist economy.

Therefore, in what follows, when considering the existing classifications of mining systems for ore deposits, we shall in each separate case touch upon the question of the scientific value of the given classification, i.e., its suitability for practical purposes.

2. A Brief Review of Existing Classifications

Many mining specialists, both in the USSR and abroad, especially in the USA, have dealt with the question of the classification of mining systems for mineral deposits. Therefore, at the present time there are very many classifications, of which the best known are those of Academician A. M. Terpigorev [2, 5], Academician L. D. Shevyakov [3], Prof. B. I. Bokii [4], Prof. I. A. Kuznetsov [5], Prof. G. A. Tsulukidze [39], Engineer V. I. Trudev [6], Tefer [7], Demanet [8], Prof. Haise and Herbst [Haise and Herbst—9], Sperr [Sperr—10], Prof. Crane [Crane—11, 12, 19], Prof. Young [Young—12, 13], Prof. McClelland and R. Peele [Mc. Clelland and R. Peele—14], and the classification adopted by the American Institute of Mining Engineers.

[AIME—15, 16], Ch. Mitke [Ch. Mitke—15, 17, 18] and Ch. Wright [Ch. Wright—25, 26].

In addition to those listed above, there are classifications proposed by other authors. This group may include the classification of Pokrovsky [20], Prof. Treptow [Treptow—5, 21], Prof. Gruner [Gruner—5, 22], Jackson and Gardner [Jacson and Gardner—53], Habet’s [5, 23], Haton de la Goupilliere [5, 24], and others. However, these latter classifications have not found wide application in our practice and in mining-engineering literature, since some of them have become considerably obsolete (Habet’s), while others do not fully enough encompass the enormous variety of mining methods used over the vast territory of the Soviet Union.

As for Pokrovsky’s classification, while distinguished by an extraordinary schematic character, it concerns more the question of the application of certain mining systems than their classification. Moreover, many of the newest mining systems, which in our country began to be widely used during the years of the first Stalin five-year plan (Sub level Stoping, Raise Stoping, and others), were not included in Pokrovsky’s classification. At the same time, even by the time it was printed in Mining Journal (1932), it was far from corresponding to the mining techniques existing during that period in the majority of mines and open pits of the USSR. In 1932 the first Stalin five-year plan ended, during which a radical reconstruction of the enterprises of the ore-mining industry was carried out. Therefore it is a very strange circumstance that the “cart” and hand drilling of blastholes became essential elements of Pokrovsky’s “classification” [0].

In the classification of Academician A. M. Terpigorev, Deman, Prof. Heise, and Herbst, systems for working coal deposits are considered predominantly. Taking this into account, we shall not discuss these classifications further, since here we consider exclusively systems for working ore deposits. The classification of A. M. Terpigorev [5] is shown in Table 1 and is given as an example of a simple, harmonious, and sufficiently complete classification of methods for working coal deposits (as applied to the state of these methods at the time to which this classification belongs).

Table 1

Classification of systems for working coal deposits by Acad. A. M. Terpigorev,

used in the course of lectures at the Moscow Mining Academy

1. Stoping by chambers, trenches, and pillars.

2. Stoping with long pillars by the Silesian method.

3. Room-and-pillar system of mining.

4. Special methods of mining; system of mining by strips: along the rise, along the strike.

III. Open-pit workings.

a) manual;
b) excavator operations.

Gefer’s classification embraces methods of mining both ore and coal deposits. Meanwhile, by the present time it has become so obsolete that it cannot be accepted even as a basis for the classification of modern mining systems, especially those used in the ore-mining industry. We shall not consider this classification further.

The most complete presentation of modern methods of mining ore deposits is found in the American classifications (Crane, Young, McClelland, R. Peele, Ch. Mitke, AIME, and Wright), and also in the classifications of Soviet scholars and mining specialists: Academician L. D. Shevyakov, Prof. I. A. Kuznetsov, Prof. G. A. Tsulukidze, Engineer V. I. Grudev, and partly in the classification of Prof. B. I. Bokii.

Among the American classifications listed above, the earliest are those of Spurr (1913), Prof. Young (1916), and Prof. Crane (1917). The most recent are the classification adopted by the American Institute of Mining Engineers (1925), Ch. Mitke (1927), and Ch. Wright (1931). In most classifications of this group, systems used in the ore industry are considered predominantly. Exceptions in this respect are only the classifications of AIME, R. Peele, and Young, in which, alongside systems used in the ore industry, certain systems of mining coal and other bedded deposits are given. But even in the latter, systems for mining ore deposits are represented more fully. Thus the classifications of American authors concern chiefly methods of mining ore deposits and other mineral deposits analogous to them. This is quite understandable, since at ore-mining enterprises in the USA an enormous variety of mining systems is currently used (more than 150 systems—18, p. 5), whereas coal extraction is carried out predominantly by the room-and-pillar system [3, p. 685].

This circumstance also partly explains the fact that, in recent times, in our literature on the mining of ore deposits and at ore-mining enterprises, the terminology adopted in the classifications of American engineers has become extremely widespread. At the same time, in certain regions of the USSR where ore is mined, as a result of not entirely correct use of American terms, such names of mining systems have appeared as “Polustoping” (Krivoi Rog), “Alaska-Bitson” (Temir-Tau), and so forth. Such names are not characteristic of the terminology adopted in the Soviet Union, are not characteristic of our language, and do not actually characterize the system itself, since this is equivalent to such names as: “Poludlinnymi stolbami,” “Polugorizontalnymi sloyami,” “Ural-Kalata,” “Sibir-Temir-Tau,” etc. The absurdity of such names, in our opinion, is quite obvious.

The classifications of Academician L. D. Shevyakov, Prof. B. I. Bokii, Prof. G. A. Tsulukidze, and Prof. I. A. Kuznetsov include systems both for coal and for ore deposits. In the first two, the systems used in the coal industry are presented more fully, while the last author set himself the task of giving an equally complete classification of methods of mining all types of minerals (solid, liquid, gaseous, ore, non-ore, coal, etc.—Table 9). To what extent—

as successfully solved by Prof. Kuznetsov; we shall express our opinion on this problem in the next section of the present work. In the classification of Eng. V. I. Grudev, only systems for the mining of ore deposits are considered.

Since B. I. Bokii’s classification was compiled before 1929 and many of the newest systems of ore mining were not included in it, we shall not consider it in detail below, just as we shall not consider a number of other classifications.

Since in the present work we consider only systems used in the underground mining of ore deposits, in what follows, when examining classifications, we shall deal only with the indicated methods, without touching upon systems that are used in open-pit operations.

3. Analysis of the principal classifications concerning systems of ore mining

Sperr’s classification (10). The author of this classification (Table 2) considers only systems of underground mining of ore deposits and, depending on the condition of the mined-out space (the method of roof control), divides them into two principal groups: a) systems with support of the mined-out space and b) systems with caving.

Table 2

Classification of systems for mining ore deposits
F. W. Sperr

(of the side and overlying rocks, or of rocks and ore). Further, as can be seen from Table 2, the indicated groups of systems are, in turn, subdivided into separate subgroups, individual systems, and their varieties. Thus, the systems of the first group are divided into three separate subgroups (“bottom-stope extraction,” “back-stope extraction,” and “underhand extraction with undercutting of the floor and roof”), and the second—into six separate systems listed in the table above. The division of existing mining methods into separate subgroups and separate systems is carried out in Sperr’s classification on the basis of the following features: the shape of the line of the stoping faces and its position relative to the level and underhand drifts, the direction, sequence, and degree of continuity of ex—

removal, the volume of ore simultaneously caved, and the method of temporary support. On the basis of these criteria, in Spurr’s classification all mining methods are divided into 15 separate systems of exploitation.

The advantages of this classification include its simplicity and brevity. At the same time, it has very substantial shortcomings. The largest and most significant shortcoming of this classification is its well-known inaccuracy and inconsistency with respect to the division of systems according to the criteria adopted in the classification as fundamental. Thus, for the division of the systems of the first group into their individual types, the basis adopted is the form of the line of stoping faces and its position relative to the drifts. On this basis, in the first group of the given classification, such systems are singled out into special subgroups in which the line of stoping faces has either a back-stepping or a fore-stepping arrangement. At the same time, in that same first group the system of “floor mining” is specially distinguished. Meanwhile, under this system, as is well known to specialists, the possibility of applying back-stepping or fore-stepping mining is not excluded. Consequently, according to this classification, there was no basis whatever for singling it out into a special subgroup. On the other hand, “pyramidal stoping” (in essence—a diagonal arrangement of the face in the longwall system) is assigned to “back-stepping stoping,” whereas here there is not a back-stepping, but a diagonal arrangement of the line of faces. Inaccuracies of this kind undoubtedly considerably diminish the practical and scientific value of the present classification. Among its other shortcomings the following must be noted: schematism, incomplete coverage of systems, ignoring the methods of maintaining the stoping space, failure to take into account the division of the extraction field into sections, and the absence of indications as to the field of application of the individual mining systems included in the classification.

The shortcomings enumerated were undoubtedly one of the reasons for the comparatively low popularity of Spurr’s classification among practical and scientific workers in the Soviet Union.

The classification of Prof. Crane [11, 12, 19]. W. R. Crane, in his book Ore Mining Methods [19], classifies (Table 3) the methods of mining mineral deposits according to the following criteria: method of mining (underground and open-pit work), method of breaking the ore and transporting it from the faces in open-pit work, thickness of veins

Table 3

Classification of mining systems for ore deposits
W. R. Crane.

and bedded deposits, the method of supporting the stoping space (supporting, backfilling, temporary leaving of ore in the worked-out space), the type of support used in stoping work, and also according to the presence or absence of caving of the enclosing rocks or of the rocks and ore. Thus, in this classification, in contrast to Spurr’s classification, the form and position of the line of stoping faces, the direction of stoping extraction, and its sequence are not taken into account at all. At the same time, it ignores such an important factor as the division of the field into extraction sections. Further, as is evident from Table 3, Crane’s classification, strictly speaking, does not give mining methods, but indicates only types of deposits according to their thickness and means of supporting (or caving) the worked-out space under systems that might be applied under the given conditions. Such a construction of the classification in fact deprives one of the possibility of using it in the practical solution of questions concerning the choice of mining systems. Moreover, in the part concerning the division of deposits according to their thickness, Crane’s classification suffers from insufficient precision. Thus, in group A (narrow veins and bedded deposits) the possibility is indicated of using square-set timbering in the mining of veins and beds of this type (group A, section 3 of Crane’s classification). This is not entirely clear, since square sets are generally used when the thickness of deposits exceeds 2.5–3 m. According to the nomenclature adopted here in the USSR, veins having such a thickness can in no way be classified as narrow veins. In addition, this classification entirely fails to take into account the possibility of supporting the worked-out space by means of temporary or permanent pillars of the mineral being mined.

Taking the above into account, we believe that the classification proposed by W. R. Crane can have very limited application both in the theory and in the practice of ore mining.

Prof. Young’s classifications [12, 13]. According to Prof. Young’s classification (Table 4), all methods of mining deposits are divided into underground and open-pit. Without touching upon open-pit work, let us consider this classification only with respect to systems applied in underground mining—

Table 4

Classification of mining systems for ore deposits

prof. G. J. Young’s

1. Mining with temporary leaving of ore in the face:

a) without ore chutes, b) with ore chutes, c) with alternating pillars.

1. Extraction in successive horizontal layers from top to bottom with caving of the overlying rocks:

a) by drifts, b) by chambers.

1. Combined mining in layers from top to bottom with partial caving of ore.

2. Mining by horizontal layers from top to bottom with partial caving of ore.

3. Mining with caving of prepared ore pillars.

4. Combined mining.

With temporary leaving of ore in the face and caving of intermediate ore pillars.

1. Mining with caving of raises.

2. Mining by drifts with undercutting of the roof bench and the floor.

For sheet-like deposits and seams.

1. Continuous mining system.

For sheet-like deposits and seams:

a) advancing from the shaft, b) retreating toward the shaft.

1. Mining by long chambers with pillars left.

2. Pillar extraction:

a) by long pillars, b) by short pillars.

II. Systems of open mining.

1. Mining by benches.

2. Mining by milling.

3. Mining by adits from the floor level of the open cut.

The latter, in the author’s classification, are divided into sixteen separate methods. As is seen from Table 4, methods 1–4 are distinguished by the form and arrangement of the lines of stoping faces; 5–6—by the method of supporting the worked-out space; 7–13—by the direction and sequence of extraction and by the method of caving the rocks, or the rocks and ore together. In addition, the classification separately singles out the “continuous system” (sect. 14), “long-chamber-and-pillar” (sect. 15), and pillar extraction (by long and short pillars—sect. 16).

Thus, the author of the present classification treats as independent such mining systems as: sublevel stoping, pyramidal stoping (open face), continuous mining, and mining by long pillars. Such a division is entirely incomprehensible to us, since sublevel extraction (open face) is nothing other than a known variety either of a continuous system or of mining by long pillars. The same is true of pyramidal extraction, which, especially with an open face, is a system of long pillars with a diagonal line of faces. Such an arbitrary division of systems is a serious shortcoming of Prof. Young’s classification.

This classification has no other particular advantages, while the inaccuracies allowed in it introduce confusion into the terminology of mining systems and make it of little use for practical application under production conditions.

Classification of Prof. McClelland and R. Peele [14]. Prof. McClelland himself classifies systems according to the method of supporting the stoping space and of caving the rocks (or rocks and ore). On the basis of these features he divides all systems into the following groups:

In structure this classification stands very close to V. Crane’s classification, with its advantages and shortcomings. However, in the book

In the Mining Engineers Handbook, R. Peele, when choosing mining systems, uses the more detailed classification shown in Table 5.

Table 5

Classification of Mining Systems

Prof. Mc. Clelland and R. Peele.

Mc. Clelland classifies the systems as follows:

I. Open stope.
II. Supported stope.
III. Stope with filling.
IV. Stope with shrinkage.
V. Caving systems.
VI. Combined methods.

When selecting systems, R. Peele divides them according to the following scheme:

A. Thin beds and deposits with strong ore and walls, with horizontal and gentle dip.

1. Longwall mining.
2. Room-and-pillar mining.
3. Overhand stoping with open stopes.
4. Methods of coal mining (room-and-pillar, pillar, longwall).

B. Thick beds and deposits with horizontal or gentle dip, with ore and wall rocks ranging from weak to strong inclusive.

1. Continuous underhand stoping.
2. Mitchell system—mining in downward slices with square-set timbering.
3. Mining methods characteristic of massive deposits (see E below).

C. Very narrow veins with steep dip, with ore and wall rocks ranging from weak to strong inclusive.

1. Preliminary exposure of the vein through barren rock.

G. Thin veins.

a) Steep dip, strong ores and wall rocks.

1. Underhand stoping with an open stope.
2. Overhand stoping with an open stope.
3. Overhand stoping with horizontal stopes and filling.
4. Pyramidal stoping with filling.
5. Shrinkage stoping system.

b) Horizontal and gentle dip, strong ores and wall rocks.

1. Continuous stoping along the rise.
2. Room-and-pillar stoping.
3. Overhand stoping with open stopes.

c) Steep dip, strong ore and weak wall rocks.

1. Mining with breast stopes.
2. Overhand stoping with horizontal stopes and filling.

d) Steep dip, weak ore and strong wall rocks.

1. Underhand stoping with an open stope.
2. Mining with square-set timbering.

e) Steep dip, weak ore and wall rocks.

1. Overhand stoping with horizontal stopes and filling.
2. Transverse stoping (crosscut system).
3. Pyramidal stoping with filling.
4. Mining in horizontal slices from top downward with caving of the overlying rocks.
5. Mining with square-set timbering.

f) Gentle veins, worked by the same methods as thin beds.

D. Thick veins.

a) Steep, with strong ore and wall rocks.

1. Underhand stoping with open stopes.
2. Underground mining by “glory hole.”
3. Mining in chambers with preliminary pillars.
4. Mining by sublevel drifts with undercutting of the floor and back.
5. Mining with an open stope and square-set timbering.
6. Mining with ore shrinkage.

b) Steep dip: ore strong, wall rocks weak.

1. Mining with square-set timbering and filling.
2. Overhand stoping with horizontal stopes and filling.
3. Pyramidal mining system with filling.
4. Combined mining systems.

c) Steep dip; weak ore and wall rocks.

1. Mining with square-set timbering and backfilling.
2. Transverse stoping (drift stoping).
3. Stoping by horizontal slices, from the top down, with caving of the overlying rocks.
4. Mining by horizontal slices from the top down with partial caving of the ore.
5. Combined methods of stoping.

d) Steep dip; weak ore and strong wall rocks.

1. Underhand stoping with an open face.
2. Stoping by horizontal slices from the top down with caving of the overlying rocks.
3. Stoping by horizontal slices from the top down with partial caving of the ore.
4. Mining with caving of prepared ore pillars (sublevel caving, block caving).
5. Combined methods of mining.

e) Gently dipping thick veins have stoping methods characteristic of massive deposits (see below, E).

E. Massive deposits and ore accumulations.

a) Ore and wall rocks—strong.

1. Underground workings, glory holes.
2. Room mining with protective pillars.
3. Mining with square-set timbering.
4. Pyramidal mining with backfilling.
5. Mining with ore storage.
6. Combined mining methods.

b) Weak ore, wall rocks from weak to strong inclusive.

1. Mining with square-set timbering and backfilling.
2. Transverse stoping (drift system).
3. Stoping by horizontal slices from the top down with partial caving of the ore.
4. Stoping by horizontal slices from the top down with caving of the overlying rocks.
5. Caving of prepared ore pillars (block caving, sublevel caving).
6. Combined methods of stoping.

In its terminology and principal features this classification differs little from the American classifications considered above. It merely gives a more detailed nomenclature for individual mining systems recommended by the author for deposits of various thicknesses, with ore and wall rocks of various strength, and with different dips (steep, gently dipping). At the same time, the listed features (thickness, dip, stability of the ore and wall rocks) are taken by the author as the basis for subdividing mining systems into separate groups.

The accepted names of individual systems show that in one case the form of the line of faces is taken as the main feature of the system (underhand stoping, etc.), in another—the type of support (square sets). On the other hand, apart from underhand and diagonal stoping, the methods of mining coal deposits used for thin bedded deposits (pillar, room-and-pillar, and longwall—Section A) are singled out, whereas both the long-pillar system and longwall can perfectly well have an underhand and diagonal arrangement of faces. Such inconsistency in dividing systems according to principal features undoubtedly reduces the scientific and practical value of this classification.

Classification adopted by AIME [15, 16]. The classification developed by the American Institute of Mining Engineers—AIME (Table 6) is one of the most recent American classifications. According to this classification, all methods of mining deposits are subdivided into open-pit and underground methods. The latter, in turn, are classified into six groups, distinguished according to strictly defined features. The first group is by the method of preparation and division of the field or ore body into stoping sections; the second and third—by the form and arrangement of the stoping faces; the fourth and fifth—by the method and extent of caving of the rocks.

Table 6

Classification of Mining Systems

Adopted by AIME

A. Open-pit operations with stripping or without stripping

I. Benching.

II. “Glory hole” mining and mills or funnels.

III. Mining of placers:

a) hand washing (washermen),
b) dredging,
c) hydraulic method.

B. Underground operations

I. Continuous extraction (stratiform, gently dipping deposits or beds):

a) by continuous level,
b) continuous pillars,
c) rooms with pillars left.

II. Underhand stoping (veins and large masses).

1. “Glory hole” and funnels.
2. Open stope:

a) with pillars left,
b) with stull timbering,
c) with square-set timbering.

III. Overhand stoping.

1. Open stope:

a) with pillars left,
b) with stull timbering,
c) with square-set timbering.

1. Stope with filling:

a) horizontal stope,
b) diagonal stope,
c) with square-set timbering,
d) with preliminary opening of the vein through barren rock.

1. Ore storage.

2. Mining by sublevel drifts.

IV. Sublevel caving (thick veins and masses).

1. Continuous level.
2. Caving by sections.
3. Caving by blocks.
4. Inclined slices.

V. Systems with ore caving (massive deposits).

1. Sublevel caving with partial ore caving.

2. Level (block) caving:

a) undercutting from the main level,
b) undercutting from sublevel drifts,
c) caving into chutes,
d) branching raises.

VI. Combined methods (massive deposits).

1. Rooms with ore storage and intermediate pillars.

Extraction of pillars:

a) by sublevel caving,
b) by sublevel caving with partial ore caving,
c) by level caving.

1. Rooms with square-set timbering and filling.

Extraction of pillars:

a) by sublevel caving,
b) with square-set timbering.

(or rock and ore). In addition, in distinguishing the last two groups, account was taken both of the method of dividing extraction fields into stoping sections and of the sequence in which they are worked. The sixth group included combined mining methods, assigned here according to features characteristic of two or three principal mining systems.

Each of the groups of systems indicated is subdivided into subgroups, separate systems, and their varieties. In some groups, as, for example, the group of systems with overhand stoping, such an order of subdivision is not always maintained, but this is explained purely by the specific features of the mining systems themselves.

In our opinion, the present classification is distinguished by strict consistency, exceptional simplicity, and a sufficiently complete coverage of modern methods for mining ore deposits. We therefore consider it one of the best among the American classifications. Unfortunately, it suffers from one substantial shortcoming, incidentally inherent in many classifications developed in the USA. In it, as in other American classifications, the form of the line of clean [[unclear: continuation cut off]]

...stopes and the method of dividing the field into extraction sections are adopted as criteria either of equal order, or else the shape of the stopes is put in first place. Meanwhile, we believe that for a number of systems, applied chiefly in thin and medium-thickness deposits, the second criterion is more general than the first. To show the correctness of this proposition, let us explain it by examples.

Let us suppose that we have solid extraction with a breast-stoping line (Fig. 1). Then, according to the AIME classification and others proposed by American engineers (Young, R. Peele), this working could be assigned to two systems: “solid” and “breast stoping,” since both types of these systems are specially distinguished in the given classifications. The question arises: to which type should the system we have taken be assigned? Using the American classifications, it is impossible to give an exact answer to the question we have posed. If, however, the shape of the stopes is considered a criterion of secondary order, then, quite correctly, we would assign this system to solid extraction with a breast stope. Here one might object, noting that in some American classifications (AIME and R. Peele) the use of solid extraction is indicated only with a gentle dip. Consequently, with such a system the line of stopes will not have a breast-shaped form; therefore the system taken as an example should be assigned to breast stoping.

Fig. 1

In that case, what would be the difference (according to the classifications) between the indicated system (Fig. 1) and breast stoping with the division of levels, sublevels into blocks or pillars (Fig. 2)? In reality there is a very substantial difference between these systems. Confusion of this kind also occurs with other systems. Therefore can such a classification be considered correct if one and the same system can be assigned in it even to two different groups? Certainly, such a classification cannot be recognized as correct and well-founded.

Fig. 2

Hence it naturally follows that the criteria accepted in the American classifications of mining systems as primary are completely unsuitable for the classification of many systems, especially those used in working thin and medium-thickness ore deposits. Unfortunately, this applies fully also to the AIME classification, although from

Table 7

Classification of mining systems

Ch. A. Mitke.

...from others it differs in greater completeness and coherence. Nevertheless, it still cannot be taken as the basis for a classification of mining systems for ore deposits.

Mitke’s classification [15, 17, 18]. The classification of Ch. Mitke (Table 7), like Speer’s classification, is based on the condition of the stope space (stope with support, stope with caving). According to this criterion, all systems are subdivided into two large groups, which are then, depending on the method of support, the method of caving, and the thickness of the veins, classified into subgroups and individual systems. The form and arrangement of the stopes are taken as the basis only in the classification of systems with caving. In the division of systems with support of the stope space, these features either are not considered at all or occupy a secondary position (systems with square-set timbering and with filling). At the same time, in constructing the classification, such a feature as the division of the ore body or extraction field into sections, as applied to systems for mining thin and medium-thickness veins and bedded deposits, has been omitted. As a result, the classification does not include the continuous system, nor mining by long and short pillars. This makes the use of this classification still more difficult. For the reasons indicated, Ch. Mitke’s classification is not especially widely used in the USSR.

Wright’s classification [25, 26]. C. Wright’s classification (Table 8) was published in mid-1931 and is therefore one of the newest classifications developed in the United States. Nevertheless, its appearance in print introduced nothing essentially new into the methodology of classifying mining systems. In our opinion, in respect to methodology it is even inferior to MacClelland’s classification, which, for all its primitiveness, appears more consistent and more coherent. The content and structure of Wright’s classification are clearly seen from Table 8.

Table 8.

Classification of systems for mining ore deposits
by C. W. Wright

Concluding the review of American classifications, we present Table 9, which gives a summary of the principal features adopted in the United States in classifying underground mining systems by main groups and subgroups. From this table it is evident that in all American classifications approximately the same features are adopted, but in dividing the systems some authors attach the greatest importance to the form and arrangement of stopes (Young, AIME), others to the condition of the excavated space (Spurr, Mitke), and so on. Only in the classifications of Crane and R. Peele are the dimensions of the deposit (its thickness) taken as the basis for dividing systems into groups. In addition, in R. Peele’s classification great importance is attached to the stability of the ore and the enclosing rocks, although the division of systems by this feature is not entirely consistent (some systems are divided by this feature into groups, others into subgroups). As for the division into subgroups and individual systems, almost all the classifications stand rather close to one another with respect to the division and naming of typical systems of mining with caving of the rock (or of ore and rock). In the other systems, however, the classifications show an extreme instability of terms. It must be supposed that this is explained by the fact that caving systems, used in mining thick ore deposits, for the most part originated and received their greatest development in the United States, where they still find very wide application. Therefore, evidently, the most stable American terminology has developed here. As for systems used chiefly in mining thin and medium-thickness deposits, especially overhand stoping and room-and-pillar mining, many of them were evidently borrowed from European practice in mining coal deposits, and therefore here too there is observed

Table 9

great variety in nomenclature and in assigning them to different groups and types.

Classification of Prof. I. A. Kuznetsov (5). As was already noted above, Prof. I. A. Kuznetsov set himself the task of constructing a classification that would encompass decidedly all types of minerals being mined at the present time. However, with respect to all minerals I. A. Kuznetsov limited himself to developing only a general classification (Table 10). He gave a partial classification only as applied to methods of mining ore deposits, without touching on the nine other classifications that he derived from the general classification (coal deposits—A₁B₁, non-ore minerals—A₁B₃, placer deposits—A₁B₄, combustible liquids—A₂B₁, etc.).

In constructing the classification, as the author indicates, he based it on the following factors: “the physicochemical state of the useful ...”

General classification of Prof. I. A. Kuznetsov
Table 10

of the mineral, the industrial-branch types of deposits, the type of mining methods used (open-pit, underground), the stage-wise nature of extraction, division into layers, the method of supporting the mined-out space, the direction of extraction, and the precise method of supporting the working space” [5, continuation, p. 43]. On the basis of such features he constructed a general classifi-

classification, which included all types of minerals, and a special (particular) one only for systems of mining ore deposits. Unfortunately, the latter classification is so complicated by minor details and excessive particulars in the matter of selecting mining systems that it has lost all practical significance.

In view of the extreme complexity and cumbersomeness of A. V.’s classification (for ore systems), we do not reproduce it in the present work. Those wishing to familiarize themselves with it may read it in Gornyi Zhurnal, No. 5, 1931.

Classification of Prof. G. A. Tsulukidze (39). In his book (39, p. 8), Prof. G. A. Tsulukidze writes: “The author has established that all existing classifications are, to one degree or another, artificial, with the exception of the group of the American Institute of Mining Engineers and Metallurgists (AIME, Young, Triner, Terpigorev), which, together with the author’s classification, may be classed as natural classifications.”

Despite a certain incorrectness in the construction of this phrase (there is no indication in the list of misprints), we quote it literally and understand it in the sense that the author considers only the classifications of “AIME” (AIME—our abbreviation), Young, Triner, Terpigorev, as well as the classification developed by him personally, to be natural.

Without touching upon the classifications of AIME, Young, and Acad. A. M. Terpigorev, analyzed by us above, let us consider how well founded the conclusion made by Prof. G. A. Tsulukidze is with respect to his own classification.

According to the classification of G. A. Tsulukidze, shown in abbreviated form in Table 11, the methods of mining solid minerals are divided into two types: “methods with extraction of minerals” and “methods with caving of minerals.”

Table 11

Classification of underground methods for mining deposits of solid minerals according to Prof. G. A. Tsulukidze
(in abbreviated form)

Systems of mining assigned to the first type the author divides into six classes (“room and room-and-pillar,” “slice,” “longwall,” “stope-and-pillar and diagonal,” “sublevel,” and “stratified”), and to the second—into three classes (“block caving,” “combined methods of chamber-stores with caving,” and “sublevel caving”). In turn, the majority of the classes are...

...is divided into subclasses, groups, etc. In particular, for example, the class “cut-and-fill methods” is divided into two subclasses: “shortwall stopes” and “sublevel breaking”; the subclass “ascending slices” (slice methods) into two groups: “horizontal” (slices) and “inclined,” etc.

Thus, from the standpoint of form, this classification appears sufficiently harmonious, and in this respect, it seems to us, it contains no particular rough spots. As for its content and its fundamental essence, in this respect the classification proposed by Prof. Tsulukidze suffers, in our view, from very substantial shortcomings. First, the very division of systems into basic types has been made in the classification in an obviously unsuccessful way. Among modern mining methods there are practically none in which breaking of solid minerals is entirely absent. Even if, in modern methods of caving by levels, breaking is of fairly substantial importance, then in sublevel caving, assigned by Prof. Tsulukidze, it is not at all clear why, to the second type, in many cases the breaking of the mineral is of greater importance than caving. Therefore it is perfectly clear that the operations—caving and breaking of the mineral (jointly)—can in no case serve as a criterion for dividing systems into separate types, since both these elements of extraction very often accompany one another. By such a criterion, in essence, almost any of the modern mining systems could be assigned to systems of the first type.

The situation is even worse with the division of systems of the first type into classes and subclasses. Thus, for example, the second class of systems of this type, “cut-and-fill methods,” is divided into two subclasses: “shortwall stopes” and “sublevel breaking.” Without speaking of the manifestly incorrect application of the term “cut-and-fill methods” to the designation of pillar systems, let us dwell on the term “shortwall stopes,” used by G. A. Tsulukidze to designate the first subclass of systems assigned to the class “cut-and-fill methods.”

In mining practice and in our mining-technical literature, the term “shortwall stopes,” like the term “longwalls,” characterizes a definite procedure for working individual sections (parts) of a seam or ore body, allocated successively for the production of stoping. When sections are worked by straight-line strips extracted in one operation over the entire length of the advancing side of the section, the extraction is called “longwalling.” In this case, after breaking, the mineral is placed along the long side of the strip, located down the dip, diagonally, along the strike, or across the strike of the mineral deposit. If, however, extraction of a strip of mineral of a definite width (2–3 m) is carried out in several operations by faces advancing chiefly along the strip itself, then this kind of extraction is called shortwall stoping.

Extraction by longwalls or shortwall stopes may be applied in the most diverse mining systems, sharply differing from one another in other very important features. This is also evident from the classification of G. A. Tsulukidze, where further on the term “shortwall stopes” is widely used to characterize the method of extraction in systems assigned by him to various classes, subclasses, and groups. The same is true of the term “longwalls.” Prof. G. A. Tsulukidze uses it now to designate an entire class of mining systems, and now to distinguish varieties of systems assigned to entirely different classes and groups (slice systems). Consequently, the features defined by the concepts “shortwall stope,” “longwall” not only do not characterize a class, subclass, or group of mining systems, but very often are not even characteristic of a single system, which, according to these features, may have several varieties.

Inaccuracies of this sort can be found in almost all the classes established by Prof. G. A. Tsulukidze. In this classification, the principal classes singled out are overhand stoping (with diagonal methods) and underhand stoping methods (Classes IV and V). Meanwhile, combined extraction (overhand and underhand) is for some reason assigned to the class “underhand stoping methods,” whereas such extraction, under this classification, could with equal right have been assigned to Class IV (“overhand and diagonal methods”). However, that would have been just as incorrect as assigning it to the group of underhand stoping methods. On the other hand, the mining system called by G. A. Tsulukidze “sublevel breaking” (?) is assigned in the classification to the class “breast-stoping methods,” despite the possibility of applying, in this system, both overhand and underhand extraction. Consequently, this system has not received a clear reflection in the classification under consideration and, evidently, with such a structure of the classification could have been assigned at once to three different classes (II, IV, and V). Such inconsistencies also occur with other systems.

Concluding here our examination of Prof. G. A. Tsulukidze’s classification, we arrive at the following conclusion: a) this classification is constructed partly on secondary, partly on uncharacteristic criteria and requires very serious revision; b) the author’s attempt to assign it to the group of natural classifications [39, p. 8], in our opinion, is as yet wholly unfounded.

In view of the fact that this classification requires substantial corrections and, in our view, is not entirely complete, we shall not dwell on it in our subsequent conclusions. Nevertheless, we believe that Prof. G. A. Tsulukidze has carried out a large and sufficiently interesting work in generalizing the existing classifications of methods for mining mineral deposits.

Classification of Engineer V. I. Grudev (6). In the classification proposed by Engineer V. I. Grudev (Table 12), only systems for mining ore deposits are considered. In its structure it is not original, since, first, it is wholly based on Prof. McClelland’s classification, and, second, it is entirely founded on the principles underlying the American classifications (AIME, Young, and others). Therefore, despite more precise formulations of the names of individual systems (“extraction in slices with caving of the overlying rocks,” “mining with sublevel breaking,” etc.), it possesses all the shortcomings inherent in the American classifications considered above.

As already noted, V. I. Grudev’s division of systems into classes was carried out according to Prof. McClelland’s method, which took as the basis of the classification the method of supporting the mined-out space (or caving). Further, the first two classes of mining systems are divided by V. I. Grudev into separate groups according to the shape of the line of production faces and the type of support used in stoping operations. And then, again, the group of systems in which square-set timbering is used is subdivided, according to the same shape of the face lines, into individual systems. Here, too, in the first class, the system of sublevel extraction is singled out separately from overhand and underhand mining, although, as we have indicated, it may have both overhand and underhand forms of faces, which is also confirmed by the author in the following section of the classification.

Thus, here there is an obvious inconsistency in the classification of systems according to the principal criteria. In this respect Grudev’s classification is in many ways inferior even to the AIME classification, which—

Table 12

Classification of Systems of Underground Mining of Ore Deposits by V. I. Grudev

the latter, despite all its shortcomings, appears, undoubtedly, much more coherent and is more consistent.

In addition, V. I. Grudev, like the authors of the American classifications, when dividing systems used for mining deposits of small and medium thickness, does not take into account the division of the field (or ore body) into extraction sections. Consequently, according to this classification

two different systems (solid and with long pillars, say, with a breast-stoping line of faces) will be regarded as one system (room-and-pillar with one or another direction of extraction—horizontal or inclined). This, at the very least, is a serious error.

Owing to the noted shortcomings, this classification can in no way be considered satisfactory, although it does cover modern methods of mining ore deposits fairly completely.

The classification of Acad. L. D. Shevyakov (3). According to the classification of Acad. L. D. Shevyakov, all mining systems are divided into three principal groups: A—underground, B—open-pit, and C—combined (open-pit and underground). In turn, all systems used in underground workings, depending on the thickness of the deposits, are subdivided into two subgroups: systems used in mining thin and medium-thickness seams and deposits, and systems for thick deposits. In addition, within this group, as an independent subgroup, “special methods” are singled out, where underground methods of exploiting liquid and gaseous minerals are considered.

Without touching on open-pit, combined, and special methods of mining, we shall consider the classification of Acad. L. D. Shevyakov only as regards underground systems for mining solid minerals (Table 13). As already noted, this section of the classification is divided into two parts. In the first, systems used in the exploitation of thin and medium-thickness deposits are considered. Here all methods of mining, according to the character of the layout of extraction fields into extraction sections, are divided into separate types and systems, which are then, according to form and ar—

Table 13

Classification of mining systems

of Acad. L. D. Shevyakov

Underground workings.

II. Development systems without division into layers.

1. Continuous:

a) continuous stopes;
b) overhand stopes: stopes without filling, stopes with filling, stopes with bench support, with filling, without filling, stopes with storage;
c) underhand stopes.

1. Long pillars (Silesian method).

2. Short pillars.

3. Chamber system without storage, with storage, with storage and filling.

4. Chamber-and-pillar system.

5. Development system with mass caving of the useful mineral.

6. System with underground mills.

III. Combined development systems.

1. Chambers with horizontal layers.

2. Overhand stope with partial storage and partial caving of the ore.

c) Special methods.

1. Extraction of liquid and gaseous minerals by boreholes.

2. Extraction by leaching.

3. Extraction by evaporation.

4. Extraction of liquid minerals by underground workings.

According to the position of the line of stoping faces, these are subdivided into their separate varieties. On the basis of these characteristics, in the first part three types of development systems are distinguished: “continuous,” “pillar” (long pillars along the strike, long pillars along the rise, short pillars), and “combined” (continuous and pillar).

Such a division of this group of methods is undoubtedly correct, strictly substantiated, and fully corresponds to the character of the development systems of both coal and ore deposits. Practically all systems used in the development of veins and bedded ore deposits (from thin to medium thickness) fit entirely into the scheme proposed by L. D. Shevyakov. Therefore this part of Academician Shevyakov’s classification (with very minor changes) can quite well be made the basis of a special classification of development systems for ore deposits.

In the second part of the section of the classification under consideration, systems used in the exploitation of thick seams and ore deposits are singled out. The systems of this subgroup are divided into three types: “with division into layers,” “without division into layers,” and “combined.” Further, as in the preceding section, the enumerated types of systems are classified into separate systems and their varieties. The basis for such a division and classification by L. D. Shevyakov consists of the following characteristics: the direction and sequence of extraction, the form and position of the stope line, the method of support and the condition of the mined-out space, the division of extraction fields, and the dimensions and form of extraction sections. Thus, in the main, all the most important characteristics are taken into account here, sufficiently fully characterizing the systems applied both in the extraction of coal and of various ores.

In both of the sections of the classification considered, L. D. Shevyakov did not take into account the methods of breaking ore (from the level of undercut drifts, by deep boreholes, by mine chambers, etc.). This characteristic is of very great importance in the classification of ore-mining systems, especially those applied in thick ore deposits. But L. D. Shevyakov’s classification is so constructed that it can easily be supplemented with systems distinguished according to this characteristic. Such an addition will not in the least change the general structure of the classification.

The analysis made of Academician L. D. Shevyakov’s classification shows that it is strictly scientifically substantiated and is equally applicable both to systems for the development of coal and of ore deposits. Together with

Thus, in this classification a simple terminology, fully understandable and generally accepted in the USSR, has been adopted, one widely used in our classical mining literature. Therefore we believe that L. D. Shevyakov’s classification can quite well be made the basis for a classification of systems for the mining of ore deposits.

Having reviewed the best-known classifications of systems for the mining of ore deposits, we arrive at the following conclusions.

a) Systems for the mining of ore deposits are presented most fully in the classifications of American authors (Young, R. Peele, Mitke, and others), as well as in the classifications compiled by Prof. I. A. Kuznetsov and Eng. V. I. Grudev.

b) Among the American classifications, the classification adopted by the American Institute of Mining Engineers (AIME) deserves the greatest attention, as the most complete, simple, and more consistent. At the same time, all American classifications (including the AIME classification) suffer from insufficient precision and consistency in the division of systems according to characteristic features. In addition, many of them are based on elements of secondary importance (the shape of the stope line, the type of support, etc.). Therefore we believe that none of them can be made the basis of our domestic classification of systems for the mining of ore deposits.

c) I. A. Kuznetsov’s classification is distinguished by extreme complexity and is therefore of little use for practical purposes, while V. I. Grudev’s is based on American classifications and has all their inherent shortcomings.

d) The classification of Academician L. D. Shevyakov, being the most rigorous, simple, and scientifically grounded, is equally applicable both to systems for mining coal deposits and to those for mining ore deposits. Along with this, it employs a simple terminology, fully understandable and generally accepted in the USSR, one widely used in our classical mining literature. Therefore we believe that this very classification should be made the basis of a special classification of systems for ore mining. This will eliminate the confusion in terminology that at present exists with respect to systems for the mining of ore deposits, and will free us from unnecessary foreign names (in the names of systems) that have become widespread in our ore-mining literature and practice.

4. Proposed classification of systems for mining ore deposits

Thus, the analysis carried out of existing classifications of systems for mining ore deposits shows that none of them, except the classification of Academician Shevyakov, can be recognized as sufficiently substantiated and suitable for practical purposes. As for the latter classification, although it constitutes an exception among the large number of existing classifications, unfortunately it nevertheless concerns, to a greater extent, methods of mining coal deposits. From this it is quite natural to draw the conclusion that a sufficiently satisfactory classification of systems for mining ore deposits does not yet exist.

As already noted above, a correctly constructed classification has enormous scientific as well as practical significance. Meanwhile, none of the existing classifications devoted specifically to systems of ore mining can be recognized as sufficiently substantiated. Therefore, in the present work a new classification is proposed (Table 14).

Table 14

Classification of Mining Systems for Ore Deposits

Compiled by G. E. Bakanov according to the classification of Acad. L. D. Shevyakov

¹) Relative to crosscuts or drifts.

in which, in our opinion, the shortcomings that existed in previously proposed classifications have to a certain extent been eliminated. At the same time, this classification is so constructed that it can be fully used in selecting mining systems both in production and in design organizations. This element, as we believe, is of the most essential importance in the classification of mining systems.

The proposed classification has been compiled according to the classification of Acad. L. D. Shevyakov. While fully preserving the general structure of L. D. Shevyakov’s classification, the terminology adopted in it, and the order of placement of the individual systems, we have introduced into it only such changes as, it seems to us, more clearly emphasize the specific features of the mining systems used in the ore-mining industry. In particular, in constructing the classification we have introduced two new sections: “Methods of supporting the stoping space” and “Additional conditions for application of the system”¹. In addition, we have made the following changes and additions to the classification of Acad. L. D. Shevyakov.

a) Systems determined by special conditions of breaking have been singled out (breaking from sublevel drifts, from inclined workings, etc.).

b) In the classification of continuous systems (Group A), extraction in strips (crosscuts) has been omitted, as having no practical significance for the ore-mining industry. For the same considerations, combined systems (continuous and pillar systems) have been omitted in this group.

c) In Group A, systems with long pillars (blocks) along the strike have been separated into a special subgroup, since they have especially wide application in the mining of ore deposits of small and medium thickness.

d) A more detailed subdivision has been made of the systems used in mining thick ore deposits (Group B).

e) Systems with caving of the ore and of the overlying rocks (sublevel and level caving) have been separated into a separate subgroup, in view of their considerable difference both from layered systems and from systems without division into layers.

f) In its content, the classification has been brought into conformity with the present state of ore-mining systems, which in recent years have been considerably improved on the basis of the experience of Stakhanovites and of the work of both our own and foreign enterprises, especially American ones.

As the basis for classifying mining systems, we have adopted the following most characteristic features: the thickness of the ore deposits; their division into extraction sections; the dimensions and arrangement of blocks (pillars) of ore prepared for extraction; the form of the lines of the stoping faces and their position relative to the development workings; the direction, sequence, and degree of continuity of extraction; the method of breaking the ore; and also the type and method of caving of the ore and of the overlying (covering) rocks. In addition, in the classification, for each system the possible methods of supporting the stoping faces (methods of roof control) and the conditions for applying one or another system are indicated. The structure and content of the proposed classification are evident from Table 14.

In concluding the question of the classification of underground systems for mining ore deposits, we express the confidence that specialists in mining will state their opinions and comments concerning the classification we propose, so as to refine it and make it still more suitable for practical purposes.

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1. Apart from thickness, which is taken as the basis for dividing the systems into groups A and B (author). ↩