RU2066697C1 - Method for cleaning of concentrates of chemical concentration from impurities - Google Patents

Abstract

FIELD: methods for cleaning of concentrates of chemical concentration from impurities; applicable in cleaning of iron and manganese concentrates. SUBSTANCE: the method includes two-stage washing of chemical concentrates with water and subsequent separation of solid phase. Concentrate after the first stage of washing is dried and calcinated at temperature of 500-600 C for 1-1.5 h. EFFECT: higher efficiency. 3 tbl

Description

 The invention relates to methods for purification of concentrates of chemical enrichment from impurities and can be used, in particular, in the purification of manganese and iron concentrates.

 To clean the concentrates of chemical enrichment from impurities, washing is currently used.

 So, there is a method of cleaning chemical concentrates by washing them with water (see E.P. Tyuftin. Washing of hydrometallurgical pulps. M. Metallurgy, 1970, p.7).

 This method is characterized by low flushing rates with a large flow rate of flushing water.

 A known method of multi-stage (2 stages or more) washing of hydrometallurgical sediments with water, followed by separation of the precipitate (O.L. Brook. Processes for washing precipitation. M. Nedra, 1973, pp. 30-31).

 However, the content of impurities in the final product processed in a known manner remains high enough.

 This disadvantage, according to the authors, is explained by the fact that impurities, mostly dissolved ones, are partially removed by washing.

 Chemical enrichment concentrates obtained by chemical deposition, for example, from solutions of iron or manganese, have a large surface and, therefore, a large adsorption capacity. Therefore, chemical enrichment concentrates contain a large number of physically and chemisorbed impurity ions, for example, calcium (Ca), magnesium (Mg), sodium (Na), etc.

Removing such impurities by washing the precipitate with water, even repeated, is ineffective. So, the concentrates obtained by chemical deposition from solutions of iron and manganese, after purification in a known manner, contained Ca ≈ 0.2% Mg ≈ 0.1% Na ≈ 0.6% K 0.4%
Such a content of impurities in the concentrate limits its further application, in particular, in the electronic industry, in the production of ferrites, etc.

 The basis of the invention is the task of reducing the content of impurities in the concentrate of chemical enrichment by reducing the adsorption capacity of the latter.

This problem is solved in that in the method of purification of chemical enrichment concentrates from impurities, including a two-stage washing with water followed by separation of the solid phase, according to the invention, after the first washing stage, the concentrate is dried and calcined at a temperature of 500-600 ^o C for 1-1.5 hours.

 It has been experimentally established that the inventive cleaning method significantly reduces the content of impurities in the final product.

 According to the authors, this effect is due to the fact that upon calcination of the washed and dried precipitate in the selected temperature regime, a directed change in the structure of the solid phase occurs, which results in a decrease in its adsorption capacity. As a result, the subsequent washing of the calcined precipitate due to desorption of impurity ions and removal of impurities previously contained in hydrated moisture is more efficient.

 Table 1 shows the results of comparative tests for the purification of manganese chemical concentrate by known and claimed methods.

The data in table 1 indicate that with an equal flow rate of washing water of 7 m ³ / t, the inventive method reduces the content of impurities: calcium ≈ 13 times, magnesium ≈ 14 times, sodium 60 times, potassium 50 times.

It was found that the claimed temperature calcination of the precipitate, equal to 500-600 ^o C, provides the maximum reduction in the content of impurities in the concentrate.

 Table 2 shows the content of impurities in the washed manganese concentrate at various temperatures of calcination of the precipitate.

 The calcination time was 1 hour.

The data shown in table 2 indicate that the calcination temperature, equal to 500-600 ^o C, provides a minimum content of impurities in the concentrate: Ca 0.02-0.015% Mg 0.01-0.007% Na 0.015-0.010% K 0 , 01-0.008%
The temperature increase above 600 ^o C is impractical, because does not reduce the content of impurities, but leads to an unjustified consumption of electricity.

Table 3 shows the indicators of the mass fraction of impurities in manganese concentrate at various times of calcination of the precipitate. The calcination temperature was 600 ^o C.

As follows from the data given in table 3, the calcination time, equal to 60-90 min, provides a minimum mass fraction of impurities: Ca - 0.015% Mg 0.007-0.009% Na 0.010-0.011% K 0.08%
Annealing over 1.5 hours does not improve the cleaning rate.

 Example 1

The iron hydroxide concentrate obtained by treating the solution of iron sulfate with ammonia was washed during repulpation at a T: W ratio of 1: 3.5. The resulting slurry was filtered on a vacuum filter. The filtrate precipitate was dried and calcined in a muffle furnace at a temperature of 530 ^o C for 1 hour. The resulting product was washed during repulpation (T: W ratio of 1: 3.5), filtered and dried. The resulting concentrate contained impurities of 0.02% Ca, 0.01% Mg, 0.01% Na and 0.01% K.

 Example 2

The manganese carbonate concentrate obtained by treating with a carbon-ammonium salt a solution of manganese chloride was washed on the filter by the displacement method at a T: G ratio of 1: 3.5. The filter cake was dried and calcined in a muffle furnace at a temperature of 570 ^o C for 1 hour. The resulting product was washed during repulpation (T: G ratio of 1: 3.5), filtered and dried.

The resulting concentrate contained calcium impurities 0.01% magnesium 0.008% sodium 0.01% potassium 0.008%
Thus, the inventive method of purification of concentrates of chemical enrichment can significantly reduce the content of impurities in them and obtain concentrates of high purity, which expands their scope, in particular in the electronics industry, in the production of ferrites, etc.

 The above examples and test results, confirmed by tables 1 to 3, indicate the industrial applicability of the invention.

Claims (1)

The method of purification of chemical enrichment concentrates from impurities, including a two-stage washing of chemical concentrates with water, followed by separation of the solid phase, characterized in that after the first washing stage, the concentrate is dried and calcined at a temperature of 500 600 ^o C for 1 - 1.5 hours

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