RU2273735C1 - Salt pile isolation in potassium mines - Google Patents

Abstract

FIELD: methods of surface mining, particularly for following natural stone treatment by covering or impregnating thereof with liquid or other flowable substances on surface.

SUBSTANCE: method involves gunning salt pit surface with waterproofing agent; covering salt pile surface with clay-and-salt mud layer in dry and hot season after salt pile hardening in at least 1.0-1.5 months after pile filling with salt. The clay-and-salt mud is sylvinite ore-dressing waste obtained from chemical factory. The clay-and-salt mud layer has 10-20 mm thickness and is formed by gunning salt pile surface with above mud material. The clay-and-salt mud is supplied into pneumatic pump receiver, wherein solid/liquid phase ratio is 1:2 - 1:3.

EFFECT: increased efficiency of salt pile waterproofing.

Description

The invention relates to various technological processes, and in particular to methods for the subsequent processing of natural stone by coating or impregnating with liquids or fluid substances on the surface.

In 2003, about 14 million tons of solid waste were stored on the surface of the earth in the territory of the Uralkali mine departments. This is two million tons more than in 2002. Now the total mass of salt dumps is about 250 million tons.

About 80 million tons of clay-salt sludge and 660 million tons of halite waste located on an area of 904 and 762 hectares, respectively, are protected at the Belaruskali Production Association. In the area of the Soligorsk kiln mines, salinization of groundwater is recorded under salt dumps and sludge storages, which has already spread to a depth of no more than 100 m. As a result of wind erosion of the salt dumps, areal pollution of soils occurs.

The brine saturation of fresh saline waste varies from 8 to 12%. The complete saturation of the waste with brines at the time of submission to the salt dump reaches 18-20%. Due to the extraction deep into the dump and evaporation, the content of the liquid phase in the dumps decreases and remains equal to 5-7%. The process of intensive squeezing of the liquid phase and simultaneously compaction of the waste lasts 15-18 hours, after which the compaction becomes hardly noticeable.

Solid halite wastes have high caking properties. Tracking of salt waste occurs not only due to compaction under the influence of its own weight, but also as a result of recrystallization of salts from squeezed brines. Moreover, the cohesion of individual grains initially manifests itself in the surface area of the blade when it dries, and after 1.0-1.5 months, the entire mass is hardened.

Salvage dumps consist of more than ninety percent of salt. The salinity of the territories adjacent to the Soligorsk mines is low, because atmospheric precipitation leads to leaching of salt components and, as a result, the salt dump is covered with a thin elastic clay film that makes salt spray difficult (Gankina V. Underground brines and garbage mountains. Republic of Belarus Council of Ministers newspaper. No. 50 (3490), March 17, 2004).

Clay-salt slurries contain up to 40-62% percent of water, 6-20% KCl, 5-24% NaCl, 0.14-7% MgCl ₂ , 0.03-0.1% CaCl ₂ , 2-5% CaSO ₄ and 5-28% of an insoluble residue, in the composition of which clay minerals predominate. These slurries in the form of a suspension are fed by pumps to the sludge storage at a ratio of solid and liquid phases from 1: 2 to 1: 3 [1, p.

A known method of isolating salt dumps in potash mines, including gunning their surfaces with waterproofing material, which is adopted as a prototype [1].

The disadvantage of this method is the low efficiency of waterproofing used for this purpose, polymer concrete due to its lack of elasticity.

The aim of the invention is to increase the efficiency of waterproofing of the dump through the use of more flexible material.

This goal is achieved by the fact that the surface of the salt dump is covered with a layer of clay-salt sludge with a thickness of 10-20 mm.

The method is as follows.

After hardening of the entire massif of the salt dump, but not earlier than 1.0-1.5 months after pouring salt into the dump in the hottest and driest period, its surface is covered with a layer of clay-salt sludge remaining after sylvinite ores are processed at galurgic factories, 10 thick -20 mm by gunning the surface of the dump truck with this slurry. In this case, the slurry in the form of a suspension is fed into the receiving hopper of a pneumatic pump with a ratio of solid and liquid phases from 1: 2 to 1: 3.

After drying of the sludge, the surface of the salt dump is covered with a strong clay crust, which prevents both wind erosion and the dissolution of salt by atmospheric precipitation. At the same time, a significant environmental effect is achieved through the use of production waste.

It should also be noted that this clay antifiltration screen has increased mechanical strength and water resistance due to the fact that it contains polyacrylamide added to the thickener to accelerate the precipitation of clay sludge [2, p. 37].

The method can be carried out, for example, using a pneumatic concrete pump SO-50 PBN (design engineer N. Marchukova). The pump is designed for transportation and layer-by-layer application on various surfaces (shotcrete) of mortars and fine concrete with a minimum mobility of 6 cm, with a aggregate fraction of no more than 10 mm, injection (inventory) of mortars and other liquids into various cavities and massifs made of concrete, stone, soil, etc. in order to strengthen them. The range of the solution supply vertically is not less than 100 m and horizontally not less than 300 m.

Information sources

1. Permyakov R.S., Romanov B.C., Beldy M.P. Salt mining technology // M .: Nedra, 1981, p. 147.

2. Processing of natural salts and brines // Reference / ID Sokolov, AV Muravyev, Yu.S. Safrygin and others; under the editorship of I.D. Sokolova. L .: Chemistry, 1985, p. 37.

Claims (1)

A method of isolating salt dumps in potash mines, including gunning their surfaces with waterproofing material, characterized in that after hardening the entire mass of the dump, but not earlier than 1.0-1.5 months after pouring salt into the dump, in the hottest and driest period the surface is covered with a layer of clay-salt sludge remaining after the sylvinite ores are enriched in the galurgic factories with a thickness of 10-20 mm by spraying the surface of the salt dump with this slurry, while the slurry in the form of a suspension is fed to reception the first hopper of the pneumatic pump with a ratio of solid and liquid phases from 1: 2 to 1: 3.