RU2675871C1 - Method of deposition of saponite pulp with the use of calcium aluminum silicate reagent - Google Patents

Abstract

FIELD: mining industry.SUBSTANCE: invention can be used in the field of the mining industry in the enrichment of diamondiferous kimberlite rocks. Method includes removing saponite-containing substances from the circulating water by the method of sedimentation. Pulp with a particle size of 71 mcm and a suspended matter content of 90 g/l is diluted with water in a ratio of 1:5, intensively mixed for 5–7 minutes. Resultant mixture is precipitated for 120 minutes due to the introduction of calcium aluminosilicate reagent composition, wt. %: CaO - 63–66; SiO- 21–24; AlO- 4–8 % and FeO- 2–4 % in an amount of from 2 to 5 g per 400–500 ml of diluted pulp.EFFECT: method provides an increase in the rate of thickening of the pulp during settling, reducing the consumption of fresh water and eliminating the discharge of industrial waste.1 cl, 4 dwg, 3 ex

Description

The invention relates to methods used in the field of mining in the processes of enrichment of diamondiferous kimberlite rocks to obtain recycled water, free from a suspension of clay materials, mainly saponite, by thickening the suspension.

A known method of compacting sediments in tailings (RF patent No. 2475454, publ. 02.20.2013) allows to accelerate the formation of saponite NaMg ₃ [AlSi ₃ O ₁₀ ] (OH) ₂ ⋅ 4H ₂ O, having a given density, from an aqueous suspension, with clarification recycled water in tailings for a closed ore processing process.

The disadvantage of this method is the complete dependence of the technological process on climatic, time, temperature indicators and, in addition, requires significant land allocation.

There is a method of coagulation used to purify a liquid representing an aqueous dispersed system (Zapolsky A.K., Kogan A.A. Coagulants and flocculants in water purification processes: properties. Preparation. Application. - L. Chemistry. 1987. - 208 s), consisting of saponite clay mineral NaMg ₃ [AlSi ₃ O ₁₀ ] (OH) ₂ ⋅ 4H ₂ O in a high degree of fragmentation (dispersed phase 20 ... 40 microns) of suspended particles. The coagulation process is carried out by introducing into the pulp a solution of aluminum sulfate (chloride), which aims to destabilize the disperse system (dispersed medium-water) and helps to connect and stick together the saponite clay mineral NaMg ₃ [AlSi ₃ O ₁₀ ] (OH) ₂ ⋅ 4H ₂ O to obtain the aggregation of saponite-aluminum hydroxide particles.

The disadvantage of this method is the high corrosive chemical activity of aluminum sulfate during the hydrolysis of Al ₂ (SO ₄ ) + 6H ₂ O = 3Al (OH) ₃ solid + 3H ₂ SO ₄ (hydrooxonium ions H ₃ O ⁺ ) with respect to technological equipment used for precipitation processes (saponite) clarification of water.

A known method of de-slamming recycled saponite-containing water and a device for its implementation (RF patent No. 2529220, publ. 09.27.2014). The object of research was saponite-containing water systems of the tailings. Exploratory tests performed using the developed electrochemical separator confirmed the possibility of efficient extraction and deposition of fine sludge (saponite), both from recycled water with sludge content up to 82 g / dm ³ , and classifier drains with a saponite mineral content of 245 ... 265 g / dm ³ . The specific energy consumption was 4-7 kWh per 1 m ^{3 of the} source or up to 5-8.8 kWh per 1 m ^{3 of} clarified water. Moreover, the electrochemical effect allows to obtain, regardless of the initial concentration of sludge in the pulp, clarified plums with a solids content of up to 20 g / dm ³ and a saponite-containing product with a solids content of up to 600 g / dm ³ when extracting more than 80%. Post-treatment of the drain in the batch thickener provides a solid phase content of 3-15 g / dm ³ .

The disadvantage of this method is the very high energy consumption: based on the material balance, the amount of recycled wastewater is 2500 m ³ / hour, which must be cleaned in order to create a closed circulation system for the complex processing of saponite ore. Even with a minimum price of 5 kWh per 1 m ^{3 of} clarified water and hourly consumption of 2500 m ³ / h. The power consumption is 12500 kW⋅h. With an annual turnover of water used in the process 12500 × 8150 = 101875000 kW. It should be borne in mind that only a saponite-containing product with a solids content of up to 600 g / dm ^{3 will} be cleaned if more than 80% is recovered.

A known method of thickening saponite suspension (RF patent No. 2448052, publ. 04/20/2012), by sedimentation of saponite particles for subsequent separation of the precipitate, followed by treatment with carbon dioxide under pressure up to 2 kgf / cm ² . The amount of carbon dioxide is introduced in an amount of up to 300 g per 1 kg of dry sediment.

The disadvantage of this method is the high consumption of carbon dioxide, which does not meet the stoichiometric proportions of the reaction, and even for these indicators, this method is not economically profitable and, in addition, excessive treatment of calcium and magnesium carbonates increases their solubility and general mineralization of water. Thus, the introduction of carbon dioxide into a saponite suspension under a pressure of up to 2 kgf / cm ² in an amount of up to 300 g per 1 kg of dry sediment does not increase its condensation rate upon sedimentation, since it increases the solubility of calcium and magnesium carbonates and worsens the properties of water, increasing its mineralization .

A known method of thickening a suspension by the method of sedimentation (Nevzorov A.L., Korshunov A.A. Study of the properties of tailings as a source of technological pressure on the environment. "Forest Journal". 2007. No. 4, pp. 140-144), adopted as a prototype in which the particles of the aqueous suspension are separated by gravity. The authors conducted laboratory experiments, which revealed that the process of sedimentation is very slow. Studies have shown that after 50 days, the deposition process did not stop, the bottom sediments are in suspension in water. Under natural conditions, when surface flows of slurry fall into the settling pond, causing sedimentation sediment to be involved, the sedimentation process of the tailings solid fraction is even slower, the sedimentation process ends in 1.5 years. The sedimentation rate of particles depends on their size, density and viscosity of the medium.

The main disadvantage of this method is the length of the process of sedimentation of the suspension with the presence of such fine particles as saponite particles, without introducing coagulants that have the ability to bind saponite particles and increase the rate of sedimentation of the pulp, the sedimentation process can lead to an increase in the occupied areas allocated for the tailings, and the presence of suspended particles of saponite will degrade the quality and increase the consumption of recycled water for the processing plant.

The technical result of the invention is to obtain purified water in accordance with SanPiN 2.1.5.980-00 with the involvement of all process water after the enrichment process, and this will allow the organization of a recycling water supply system of the processing plant, which allows to reduce the consumption of fresh water, and to eliminate the discharge of industrial effluents, and the use of natural mineral inorganic substances that are part of the calcium aluminosilicate reagent will reduce the load on the environment of the mining region and to increase the sedimentation rate of the pulp.

The technical result is achieved by the fact that the pulp with a fineness class of 71 μm and a suspended matter content of 90 g / l is diluted with water in a ratio of 1: 5, stirred vigorously for 5-7 minutes, and then the resulting mixture is precipitated for 120 minutes by introducing a calcium-aluminosilicate reagent with a composition in wt. . %: CaO - 63-66; SiO ₂ - 21-24; Al ₂ O ₃ - 4-8% and Fe ₂ O ₃ - 2-4% in an amount of 2 to 5 g per 400-500 ml of diluted pulp.

The method of deposition of saponite pulp using calcium aluminosilicate reagent is illustrated by the following figures:

FIG. 1 - the initial saponite pulp diluted with water in a ratio of 1: 5 to which calcium-aluminum-silicate coagulant was added and mixed for 5-7 minutes at room temperature;

FIG. 2 - saponite pulp, subjected to sedimentation for 30 minutes at room temperature;

FIG. 3 - saponite pulp, subjected to sedimentation for 75 minutes at room temperature;

FIG. 4 - saponite pulp, subjected to sedimentation for 120 minutes at room temperature;

The method is as follows. The saponite pulp is diluted in a glass with water (Fig. 1) in a ratio of 1: 5 at room temperature, the mixing process is carried out for 5 to 7 minutes. From the solution thus obtained, saponite is precipitated for 120 minutes (Fig. 2) by coagulation with the introduction of a calcium-aluminosilicate reagent, depending on the consistency of the pulp (the content of suspended particles varies in the range of 90 g / l, the mineral fineness class is -71 μm), in quantity from 2 to 5 g. Saponite precipitation occurs at room temperature. Saponite is deposited at the bottom of the glass in the form of a suspension (Fig. 3), the upper layer of pure water is used to wash diamondiferous ore (Fig. 4).

Example 1

A sample of the return water from the spiral classifiers after the enrichment process of diamondiferous saponite clay is presented in a volume of 250 ml, the mineral fineness class is 71 μm, the suspended solids content of 90 g / l was diluted (1: 1) to 250 ml with pure water in measuring cups with the use of 2 g of calcium aluminosilicate reagent (coagulant composition in wt.%: CaO - 63-66; SiO ₂ - 21-24; Al ₂ O ₃ - 4-8% and Fe ₂ O ₃ - 2-4%) after intensive mixing in within 2 minutes were brought into a statistical simulation of the deposition process. After 2 hours, 10 ml of pure water without suspensions was observed, the density of the precipitate was 14.4%) by solid.

Example 2

A sample of the return water from the spiral classifiers after the process of enrichment of diamondiferous saponite clay is presented in a volume of 120 ml, the mineral fineness class is 71 μm, the suspended matter content of 90 g / l was diluted (in a ratio of 1: 3) to 360 ml with clean water in measuring cups with using 3 g of calcium aluminosilicate reagent (coagulant composition in wt.%: CaO - 63-66; SiO ₂ - 21-24; Al ₂ O ₃ - 4-8% and Fe ₂ O ₃ - 2-4%) after vigorous stirring in within 5 minutes were brought into a statistical simulation of the deposition process. After 2 hours, 53 ml of pure water without suspensions was observed, the density of the precipitate was 12.3%) by solid.

Example 3

A sample of the return water from the spiral classifiers after the enrichment of diamondiferous saponite clay is presented in a volume of 80 ml, the mineral fineness class is 71 μm, the suspended matter content of 90 g / l was diluted (in a ratio of 1: 5) to 400 ml with pure water in measuring cups with using 5 g of calcium aluminosilicate reagent (coagulant composition in wt.%: CaO - 63-66; SiO ₂ - 21-24; Al ₂ O ₃ - 4-8% and Fe ₂ O ₃ - 2-4%) after vigorous stirring in within 7 minutes were brought into the statistical modeling of the deposition process. After 2 hours, 120 ml of pure water without suspensions was observed, the density of the precipitate was 10.4%) by solid.

The presented examples allow us to conclude that due to the higher dispersion and, accordingly, the exchange capacity of saponite compared with other mineral groups of montmorillonite, as well as a density of 2.3-2.5 g / cm ³ and a Moss hardness of 2.5 and size particles of 40 microns saponite has an extremely high stability in the aquatic environment.

Thus, intensive mixing for 5-7 minutes of pulp with a fineness class of 71 microns and a suspended matter content of 90 g / l and diluted water in a ratio of 1: 5 and the introduction of calcium-aluminosilicate reagent (coagulant composition in wt.%: CaO - 63-66 ; SiO ₂ - 21-24; Al ₂ O ₃ - 4-8% and Fe ₂ O ₃ - 2-4%) in an amount of 2 to 5 g per 400-500 ml increases the rate of its thickening during sedimentation, due to that the obtained reagent has coagulation properties, which binds saponite particles to aggregated aggregates, this provides the possibility of not only sedimentation particles at the bottom and ejection of pure water on the surface, but the binding saponite slurry tailings dam from further destruction.

Claims (1)

The method of deposition of saponite pulp, including the extraction of saponite-containing substances from recycled water by settling method, characterized in that the pulp with a particle size of 71 μm and a suspended matter content of 90 g / l is diluted with water in a ratio of 1: 5, intensively mixed for 5-7 minutes and then obtained the mixture precipitated for 120 minutes due to the introduction of calcium-aluminum-silicate reagent composition in wt. %: CaO - 63-66; SiO ₂ - 21-24; Al ₂ O ₃ - 4-8% and Fe ₂ O ₃ - 2-4% in an amount of 2 to 5 g per 400-500 ml of diluted pulp.

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