DETERMINATION OF TECHNICAL AND ECONOMIC INDICATORS FOR EXPERIMENTAL SYSTEMS FOR MINING THICK SEAMS IN KUZBASS

Prof. D. A. Strelnikov

1. Introduction

The subject of the present article was put forward by us in connection with the work of a conference organized by Kuzbasskombinat in November 1937 to discuss a number of proposals in the field of new systems for mining thick seams in Kuzbass. During the first half of 1938, by order of the Kuznetsk Scientific Research Coal Institute, this subject was further developed by us; moreover, not only were certain technical and economic indicators proposed for experimental systems for mining thick seams in Kuzbass, but forms were also worked out for the primary and subsequent documentation of all data which ultimately led to the technical and economic indicators proposed by us. Both the indicators themselves and the forms for documenting data on experimental systems for mining thick seams in Kuzbass were approved by the Kuznetsk Scientific Research Coal Institute in July 1938, and subsequently were applied by it at its experimental sections in the mines of the Prokopyevsk and Kiselevsk coalfields.

Our proposals regarding the technical and economic indicators of experimental mining systems have not lost their theoretical and practical interest even at the present time. The need for them was prompted at the time by the following considerations and circumstances:

During 1938, at the Sudzhenka, Kemerovo, Kiselevsk, and Prokopyevsk coalfields, experiments were to be carried out on a number of systems, new for Kuzbass, for mining thick seams: 1) horizontal slices with stowing and their extraction in descending order at Sudzhenka and Prokopyevsk; 2) inclined slices, both in ascending and in descending order, using dry and hydraulic stowing at Kemerovo, Prokopyevsk, and Kiselevsk; 3) proposals for new variants of inclined slices (the so-called “herringbones,” “half-herringbones,” and transverse-inclined slices); 4) a system with a shield and, finally, a system of diagonal slices at Kiselevsk and Prokopyevsk. In previous years, similar experiments

during implementation were not subjected to systematic study; the data collected on them, and especially the technical and economic indicators, were far from complete and were of a random nature, and often, for one reason or another, they constituted a “secret” of the immediate managers conducting these experiments.

This is why it was absolutely necessary to establish:

1) which technical and economic indicators, as applied to each of the experimental variants, should in general be taken into account;

2) what additional data on experimental mining systems should, in parallel with the conduct of these experiments, be recorded, collected, and processed; and

3) by which indicators these variants could later be compared with one another and conclusions drawn as to their application in the future.

Thus, the main purpose of the present work was to ensure a more substantiated and uniform evaluation of each variant of the experimental mining systems for thick seams in Kuzbass and to compare them with one another.

2. Critique of the Current State of Technical Reporting on Mining Operations at Kuzbass Mines.

The technical reporting currently used at the mines of Kuzbass is operational-statistical reporting; it is presented in the form of the so-called “production and technical report of the mine,” and, according to reports from the field, the data obtained from such reports make it possible to draw only general conclusions for the Kuznetsk Combine as a whole; to a very small extent do they satisfy the trusts, since they provide mainly average statistical figures for individual technical and economic indicators; finally, the data of the “production and technical reports of the mine” in no way satisfy the engineering, technical, and economic personnel working directly at the mines. What accounts for the latter?

1. Such an essential question as the technical and economic analysis of experimental mining systems—those being applied at the above-mentioned mines, or planned for implementation in the future—cannot be resolved on the basis of only one previous “production and technical report of the mine.” This circumstance alone is already the most significant shortcoming of the existing form of reporting.

2. The “production and technical report of the mine” is entirely unable to take into account the diversity even of typical mining systems, not to mention variants of one and the same mining system applied under conditions that are often substantially different from one another. Nevertheless, the need to evaluate individual mining systems under given specific conditions, or their variants, and to compare mining systems with one another according to

by individual indicators is not uncommon; and then one has to make various kinds of additional “adjustments,” decipherments, or, as it is commonly called, introduce “off-system reporting.”

1. The same “production-and-technical report of the mine” does not at all reflect the consumption of the principal materials, and these data, again, can most often be obtained only for the mine as a whole and have to be taken from other sources.

Thus, the inadequacy of the “production-and-technical report of the mine” both for operational purposes and for purposes of technical-and-economic analysis is quite clear.

In addition to the “production-and-technical report of the mine,” the mines of Kuzbass keep a so-called work journal. The very name of this document suggests that perhaps from it we shall obtain a whole series of data needed for analyzing the work of the mine as a whole, of its individual sections, and, in particular, for resolving all questions concerning the value and the technical-and-economic indicators of the experimental mining systems being used. In reality, however, the internal content of the “work journal” ensures analysis of mining systems to a very small degree, gives the operational worker little in his day-to-day work, and it serves (the “work journal”) primarily the purposes of bookkeeping, more often turning into a “summary of expenditures.” That is why neither operational engineering-and-technical workers, planners, nor engineers for technical matters make use of the “work journal”; it proves to be a journal only for the mines’ accounting personnel.

Such a situation with the “work journal” cannot be regarded as normal; it must be thoroughly revised.

Thus, from the foregoing it follows that the existing technical reporting at the mines of Kuzbass is not capable of solving our tasks.

That is why the question quite naturally arose of the need to clarify the entire body of information and indicators that we should normally possess regarding experimental systems for mining thick seams in Kuzbass.

3. Necessary information and technical-and-economic indicators for experimental systems for mining thick seams in Kuzbass.

1. With respect to each mining system designated for study, first of all information must be provided on the natural conditions of occurrence of the corresponding seam where it is applied; on the thickness of the seam (normal and horizontal), its dip; on the character and variation of the latter along the strike and dip of the seam within the limits of the working horizon; on the strength of the coal, cleavage (if any), gas-dust and water content of the seam; on the chemical composition of the coal and on its technical properties; on the composition and properties of the roof and floor of the seam, its interbeds.

beds or inclusions, if any are present in the seam, their locations, thickness, composition and properties; on the presence and character or absence of disturbances in the given seam; on the relation of the seam being worked to the workable coal seams lying above and below it; on the composition, properties and thickness of the rocks separating the seam being worked from the overlying workable seam; on the thickness of the latter, and the procedure and method of its working.

To all the preceding material there must be attached a vertical section of the seam being worked, with its roof and floor and the enclosing rocks up to and including the nearest overlying workable seam, indicating the thickness of the rocks and coal seams.

Then the following must be taken into account:

1. The horizon of the experimental workings (ventilation and main drifts) and the condition of the workings at the beginning of their conduct in the given seam.

2. The elements of the experimental extraction field and its extraction sections. A graphic representation of the experimental system for mining a thick seam¹) (at a scale of 1:500 or 1:1000) and in no fewer than three projections (in the form of a vertical section along the strike, a vertical section along the dip, and characteristic horizontal sections), showing the mutual arrangement of all workings (development and extraction workings), indicating the advance of the extraction faces relative to the faces of the development workings used in this experimental mining system, and the normal procedure for conducting the latter.

3. Normal cross sections of all development workings used in the given experimental (or studied) mining system (at a scale of 1:50—1:100).

4. A representation of all mining operations performed in driving the development workings (drifts of various designations, furnaces, crosscuts, raises, etc.): a) coal extraction (consisting of undercutting, breaking, and delivering coal from the faces of the development workings); b) extraction or blasting of rock from the sides or from interbeds—inclusions in the seam being worked; c) installation of temporary and permanent supports; d) laying of temporary and permanent tracks; e) ventilation of faces; f) equipment associated with ventilation, drainage, power supply, installation of various mechanisms and machines in the faces of development workings, etc.; g) with obligatory depiction of the performance of all the preceding operations over time, in space, with respect to the expenditure of labor, materials and energy, the quantity of coal and rock delivered, with respect to the organization of work and labor force by shifts, days, qualifications of the workers assigned to them²); with the shift productivity of the workers; with shift, day-

¹) Both in the form in which it was actually carried out and also according to the design. D. S.

²) In the form of plans and charts of attendance, if cyclicity is carried out or planned. D. S.

daily and monthly productivity and the percentage utilization over time of all mechanisms used in driving these development workings, and also with allowance for the normal productivity of the mechanisms used. The per-shift, daily, and monthly advance of the development workings. The cost of 1 linear m, 1 cubic m, and 1 t of coal obtained in driving the development workings and, finally, the amount of coal extracted from development workings as a percentage of the total amount in the given extraction panel.

Diagrams and drawings reflecting the performance of all the above-listed work in driving the development workings must be appended to the material under item 5.

1. Stoping operations carried out under the given experimental mining system must also be reflected in all their stages: a) making the undercut (if one is used), b) breaking down the coal (separating the rock from the interbeds and inclusions, if any), c) delivering coal from the stoping faces and within the latter to the nearest drift (delivering rock, if any, and if its delivery is carried out), d) supporting the stoping faces, e) caving the roof or backfilling the worked-out space with waste rock, or both together, taking account of their performance only within the limits of the stoping face of the given extraction panel, f) the organization of work and labor into individual stages and their combinations with one another in time and space¹, g) the expenditure of labor by qualifications for each stage of work, as well as of materials and energy, broken down by shift and by day and per 1 t of coal extracted from the stoping faces, h) determining the per-shift and monthly productivity of workers of all qualifications, i) determining the per-shift, daily, and monthly productivity of all mechanisms used in stoping extraction and the percentage utilization of the latter over time, with allowance for their normal productivity, j) the per-shift, daily, and monthly advance of stoping faces, k) the number of cycles per day and per month, m) losses of coal in the stoping faces, and n) ash content of the coal.

2. General district operations of the experimental extraction panel: a) transportation within it along intermediate drifts, b) delivery of backfilling materials, likewise along intermediate drifts, c) delivery, installation, and dismantling of equipment used under the given experimental mining system, d) ventilation, e) supply of power, f) routine repair of workings; all these data must be recorded and calculated only within the limits of the given experimental extraction panel.

3. The advantages and shortcomings that become apparent during the conduct of the experiments and that are inherent in the given mining system (or its variant), as well as when compared with mining systems previously used in the given seam.

1. Conditions of the experimental work that distorted the results of the experimental application of this mining system.

2. Accidents that occurred during the experiments; their location, nature, number, and the conditions under which they occurred, and the causes that gave rise to them.

3. Final information and technical-and-economic indicators for each experimental mining system or its variant:

a) A brief description of the natural conditions of the seam being mined (in accordance with item 1, see above).

b) The principal elements of the mining system being studied (in accordance with item 3, see above).

c) The number of linear and cubic meters of preparatory workings per 1000 \(t\) and as a percentage of the total output from the given experimental extraction field.

d) The amount of coal issued from the faces of preparatory workings of one extraction field per shift, per day, and per month.

e) The amount of coal issued from the stoping faces in one extraction field per shift, per day, and per month.

f) The amount of coal issued from all faces (both from preparatory workings and from stoping faces) of one extraction (experimental) field under the given mining system (or its variant) per shift, per day, and per month (the sum of the coal output under points d and e).

g) The percentage of coal losses in the extraction field (in pillars; coal not extracted though mined; spillage, etc.) and the quality of the coal.

h) The consumption of timber materials (in cu. m) for supporting preparatory and stoping workings, and the cost of these materials under the given mining system (or its variant), per 1000 \(t\) of coal extracted in total from the given seam within the limits of one extraction field.

i) The consumption of stowing materials in cu. m per 1 \(t\) of coal mined within the limits of one extraction field under the given mining system (or its variant).

j) The consumption of explosives (in cases where they are used) and their cost per 1 \(t\) of coal within the limits of one extraction field.

k) The consumption of energy (electricity, compressed air) and its cost per 1 \(t\) of coal mined within the limits of one extraction field.

l) The total consumption of labor power and its cost per 1 \(t\) of coal mined within the limits of one extraction field, free-on-main haulage roadway.

m) The shift productivity of a worker under the given mining system (taking into account stowing operations within the limits of the extraction field), free-on-main haulage roadway.

n) The number of mechanisms (and equipment) used under the given mining system (or its variant) per 1000 \(t\) of coal mined from one extraction field, and the degree of their utilization as a percentage of time and of their normal productivity.

p) Cyclicity of operations in stopes and in faces of development workings; reserves.

r) Depreciation deductions, the cost of repair and maintenance of workings, and the cost of repair of mechanisms within the extraction field, attributable to 1 t of coal in total coal output.

s) The total cost of 1 t of coal under all the preceding expenditures—free on the main haulage drift—for the given mining system (or its variant).

t) Data on accidents under the given experimental mining system.

1. Ways of further improving the given experimental mining system (or its variant).

The necessary information and technical-and-economic indicators concerning experimental systems for mining thick seams in Kuzbass, cited above, may be regarded as a general instruction for collecting and processing data on these systems.

Some objections may be raised by the data on the main development workings, which are often common to many mining systems; nevertheless, we think it is absolutely necessary to have these data as well, so that, in all cases of evaluating one or another mining system or comparing it with other mining systems, there will be data on all workings within the limits of the given extraction field. This becomes all the more necessary when one and the same mining system is applied on seams of different thickness, when we would consider it more correct to judge the given mining system, or to compare it with another, on the condition that all development workings existing within a single extraction field are taken into account.

Data on secondary development workings that are characteristic of, or inherent only in, the given mining system or its variants are unquestionably necessary.

It must be assumed that such data on experimental systems for mining thick seams in Kuzbass require no additional proof of their necessity.

It should be noted that, under the operating conditions of our mines in Kuzbass, even now (for example, in the “Stalinugol” trust) the need is being advanced to establish uniform technical-and-economic indicators by which it would be possible to evaluate not only experimental mining systems, but also the ordinary systems widely used—with one or another deviation in their application in the given trust at its individual mines and seams. We think that the data cited above on experimental mining systems can also be transferred to the ordinary mining systems used in the mines of Kuzbass, provided that possible reductions and simplifications are introduced into them.

1. In the form of planograms and time schedules, if cyclicity is carried out or planned. D. S. ↩