RU2230190C2 - Method for extraction of potassium deposit in areas of replacement of silv enate by rock salt - Google Patents

Abstract

FIELD: mining industry. SUBSTANCE: method includes boring of exploration wells from the surface, contouring of potassium deposit, replacement areas, driving of cleaning and preparing excavations by combines. In area of replacement area expansion surface seismic prospecting according to method of common deep point is performed, as well as geomorphologic mapping of earth surface, and an approximate location of displacement basin in above-salt rock and in water-protective covering. Then in rock salt under silvenate beds shaft seismic surveying researches are performed and displacement basin is contoured at level of extracted beds. After that limitations are sad for driving of cleaning and preparation excavations in area of edge portion of displacement basin. EFFECT: prevention of potassium mines flooding. 1 ex

Description

The invention relates to mining and can be used in underground mining of potash deposits in the zones of replacement of sylvinite with rock salt.

The Verkhnekamsk potash deposit (VKMKS) is unique in reserves and has a length of about 200 km in the meridional direction and about 55 km in the latitudinal direction. The area of development of potash salts is 3750 km ² . The development of the Verkhnekamsk potash deposit was started back in 1932. Until 1986, the development of salts was carried out by seven mines located in the central and southern parts of the deposit. In 1986, as a result of a violation of the water protection stratum, the world's largest mine of the Third Bereznikovsky Potash Mine with a capacity of 8 million tons of ore per year was flooded and irretrievably lost.

After the flooding of the mine, the intensity of research work aimed at studying the geology of VKMKS sharply increased. At the same time, the priority in research currently belongs to the study of water-proof strata, tectonics and mineral transformations.

A water-proof stratum is an impermeable part of a mountain range located between a mined-out reservoir of potassium-magnesium salts and a horizon containing suprasalt low-saline waters.

When mining potash and magnesium salts in the field, sylvinite substitution zones with rock salt are often found. In the substitution zones, the process of replacing sylvinites with rock salt as a result of the removal of potassium by ascending sodium chloride solutions was carried out. In such zones, a significant (two or more times) decrease in the thickness of sylvinite layers is recorded. For different authors, these zones have a different name: “zone of galvanization of sylvinite”, “zone of dilution”, “zone of thermodynamic dilution”, etc. [1].

In the area of substitution zones, due to a decrease in the volume of the salt mass, secondary compaction of rocks is carried out, a displacement mold is formed, in the marginal parts of which, due to the action of horizontal tensile deformations, the development of discontinuous dislocations, including in the water-proof thickness, is possible.

The maximum number of substitution zones is currently recorded on the territory of the mine of the Second Bereznikovsky Potash Mine, uncovered by mine workings - about 150. Among them, large ones with a length along the long axis of more than 1 km, medium ones from 1.0 to 0.1 km and small ones are distinguished less than 0.1 km.

The invention has no analogues.

The purpose of the invention is to prevent flooding of potash mines by maintaining the integrity of the water-proof stratum in the process of cleaning excavation of potash ores.

This goal is achieved by outlining the displacement trough at the level of the mined sylvinite strata, after which restrictions are introduced on the sinking and preparatory mine workings in the region of the edge of the displacement trough.

The method is as follows.

Exploratory wells are drilled from the surface, a potash deposit is delineated, sylvinite substitution zones are replaced by rock salt, and mining and preparatory workings are carried out by combines. In the area of the substitution zone distribution, determined according to detailed exploration data, ground-based seismic exploration is carried out according to the common deep-point technique. The specified operation is carried out in a known manner [2]. Then carry out geomorphological mapping of the earth's surface. The process of replacing sylvinites with rock salt as a result of the removal of potassium by ascending sodium chloride solutions is essentially karst and is most often found in the modern relief in the form of funnels of various shapes [3]. Having determined the coordinates of the funnel on the earth's surface, they also establish approximately the location of the trough of displacement in suprasalt rocks and in the water-proof mass. Then, in the underlying sylvinite strata of rock salt, exploration mine workings are excavated, in the roof of which wells are drilled on sylvinite strata to determine the boundaries of the replacement zones, mine seismic surveys are carried out. These studies are carried out in a known manner [4]. Next, the trough of displacement at the level of worked out horizons is outlined. After that, restrictions are introduced on the sinking of mining and preparatory mine workings in the region of the regional part of the displacement trough.

An example implementation of the method. On the Bygelsko-Troitsky section of the VKMKS, exploratory wells were drilled from the surface and the potash deposit was outlined. In the process of exploration, well No. 467 was drilled, which exposed the sylvinite substitution zone with rock salt. Then, 4 prospecting drifts were carried out under the replaced sylvinite strata in the underlying rock salt within the 5 southwestern panel of the mine field of the Fourth Bereznikovsky Potash Mine. In the substitution area, seismic surveys were carried out, the interpretation of the results of which revealed a loss of correlation of the reflecting boundaries in the water column. The position of the correlation loss zone of the reflecting boundaries coincided with the edge of the trough of the displacement of the compacting, after removal of potassium, salt rocks from them.

A geomorphological mapping of the earth's surface was carried out, and a trough of displacement of supersalt rocks southwest of the displacement zone in the underlying rock salt was revealed. This direction corresponds to the direction of the flow of leaching potassium solutions (towards the arch of the Bereznikovsky uplift).

From exploratory drifts up to sylvinite formations, 14 wells were drilled, refining the geological structure of the area of the substitution zone. As a result of the analysis of the obtained geological and geophysical materials, a replacement zone was outlined at the level of the developed AB and Krasny II formations and the leaching rock displacement mold located inside it. After that, restrictions were introduced on the sinking of mining and preparatory mine workings in the region of the regional part of the displacement trough.

Sources of information

1. 3ones dilution / substitution. In: Petrotectonic Foundations for the Safe Operation of the Verkhnekamskoye Potassium and Magnesium Salts / Ed. Doctor of Geology and Mathematics N.M. Dzhinoridze // SPb-Solikamsk: OGUP Solikamsk, printing house, 2000, p.130-153.

2. The effectiveness of seismic exploration of the MOGT in solving tectonics. In: Petrotectonic Foundations for the Safe Operation of the Verkhnekamskoye Potassium and Magnesium Salts / Ed. Doctor of Geology and Mathematics N.M.Dzhinoridze // SPb-Solikamsk: OGUP Solikamsk, printing house, 2000, p. 82-105.

3. Fur coat B.C. Ancient surface alignment, the principles of their selection and some patterns of relief formation of the Urals. Materials on the geomorphology of the Urals, issue 2. / Ed. I.P. Gerasimova. - M .: Nedra, 1971, p.20-29.

4. Sapfirov I.A. Mine tasks of seismic exploration UrB RAS. - Ekaterinburg, 1996, 167 p.

Claims (1)

A method of developing a potash deposit in sylvinite substitution zones with rock salt, characterized in that exploration wells are drilled from the surface, potash deposits, substitution zones are delineated, combines are being cleaned and mined in the area where the substitution zone is spread, ground seismic exploration is performed according to the common deep point technique , geomorphological mapping of the earth's surface and determine the approximate location of the displacement trough in suprasalt rocks and in water a protective stratum, then exploration mine workings are drilled in the underlying sylvinite strata of rock salt, roofs are drilled into sylvinite strata, mine seismic surveys are carried out and a mold trough is delineated at the level of the worked strata, after which restrictions are imposed on the mining and preparation mine workings in the region of the marginal part of the displacement trough.