On the Absorption of Metal Ions by Placer Minerals
Abstract Generated abstract
This study examines the sorption of selected heavy metal ions by placer minerals, focusing on ilmenite and zircon whose grain surfaces may carry clayey films capable of accumulating metals. Purified mineral fractions were exposed for two years to salt solutions, after which copper, lead, and zinc contents were measured in the clarified suspensions and sorption was calculated relative to mineral surface area. The results indicate that ilmenite has a higher sorption capacity than zircon, especially for lead and copper, and suggest a relationship between sorbed metal quantity and the amount of clayey material present in surface films.
Full Text
ON THE ABSORPTION OF METAL IONS BY PLACER MINERALS
S. A. Babenko
(Presented by the scientific seminar of the Department of PMAChP, ChTF)
Placer minerals contain a clayey film on their surface, in greater quantity on minerals of the electromagnetic fraction [1]. According to available data [2], the clayey material of the films has the ability to accumulate metal ions. In this connection, the present work investigated the possibility of sorption of ions of certain heavy metals by placer minerals: ilmenite and zircon. These minerals were separated from placers by concentration on tables and were separated on an electromagnetic separator. The carefully purified minerals had a grain size of 0.1 mm; the content of foreign minerals in ilmenite was 0.4% (leucoxene, zircon), and in zircon—9.7% (leucoxene, rutile); the specific surface, determined by the Hinshelwood method [3], was 480 cm²/g for ilmenite and 270 cm²/g for zircon.
The procedure for conducting the experiments was as follows. Equal quantities of the minerals by weight (100 g) were poured into jars with ground-glass stoppers, into which 200 ml of a solution of a definite salt was added. After two years of storage, the content of metal ions was determined in the clarified part of the suspension.
The results of the experiments (Table 1) indicate a greater sorption capacity of ilmenite in comparison with zircon: for zinc by a factor of 1.4,
Table 1
Sorption of metal ions by ilmenite and zircon
| Minerals | Cu | Pb | Zn |
|---|---|---|---|
| Ilmenite | 0.137 | 0.273 | 0.210 |
| Zircon | 0.045 | 0.074 | 0.140 |
Sorbbed per 100 cm² of mineral, mg of metal
for copper by a factor of 3.1, and for lead by a factor of 3.7. Ilmenite sorbs lead in the greatest quantities, then zinc and copper. In zircon, zinc is sorbed most of all, followed by lead and copper.
Thus, ore minerals sorb ions of heavy metals on their surface, and there is a direct dependence between the amount of sorbed metal and the amount of clayey material in the film.
References
-
S. A. Babenko. Flotation of ilmenite from sands containing humic substances. Izv. SO AN SSSR. Series of Technical Sciences. Issue 3, No. 10, 1963.
-
A. M. Tsekhomsky. On the structure and composition of films on grains of quartz sands. In: Weathering Crust. Publishing House of the Academy of Sciences of the USSR. Issue 3, 1960.
-
E. E. Sergo, V. A. Bunko. Sampling, control, and automation of technological processes at concentration plants. Ugletekhizdat, 1957.