SU916464A1 - Process for hydrochemical treatment of nepheline slurry - Google Patents

Description

The invention relates to the technology of production of alumina, in particular to the hydrochemical treatment of nepheline sludge, waste processing of aluminosilicate

ORE. ·.

The method of hydrochemical treatment of nepheline sludge is known, which consists in the fact that nepheline sludge is subjected to hydrochemical processing with soda solution, 5U _{2 is} extracted, followed by roasting of the raw mix at 1400–1500 ° С [1]. ^{, 0}

The disadvantages of this method are the low degree of caustification with soda solution, the low quality of products made from Portland cement due to the high content of alkalis in Portland cement clinker; the need for ¹⁵ roasting of the raw mix at high temperature (1400–1500 ° C); as well as a small concentration of silica in soda solution after hydrochemical treatment.

The closest to the proposed by tech- nical ²⁰ is essentially a method of hydro-chemical treatment sludge nepheline alkaline solution consisting in that

2

the sludge is pretreated with carbon dioxide in an aqueous medium at 25–95 ° C for 2–6 h, then alkaline treated with a solution of caustic sodium at a concentration of Ma ₂ O 25–500 g / l, followed by thickening and washing the sludge [21.

The disadvantages of this method are the complexity of the production technology for single-component raw mixture of Portland cement clinker, low silica recovery of dicalcium silicate, low efficiency of nepheline, the high concentration of caustic used shelochi transition ion CO ₂ ^"2 of carbonized nepheline slurry in an alkaline solution; the complexity of the production technology of portland cement and clinker, associated with the installation of additional units and devices, high energy costs.

The purpose of the invention is the intensification of the process of hydrochemical treatment of nepheline sludge.

This goal is achieved by the fact that in the method of hydrochemical treatment of nepheline 3. 916464 4

sludge alkaline solution nepheline sludge is treated with potash soda solution with a concentration of K ₂ CO ₃ . 300-480 g / l; Ma ₂ 0iar1 85-120 g / l with _J: T *. (4.5-5): 1 and 120-150 ° C for 15-.90 min. five

The proposed method of hydrochemical treatment of nepheline sludge allows reducing the silica content in nepheline sludge from 30% to 17-20% and using it as a one-component mixture in cement production, as well as simultaneously tasking potash soda solution for reuse in hydrochemical treatment of nepheline concentrate.

Nepheline-15 slurry was used for research, the grinding fineness is 0.15 mm and the chemical composition,%: 5ϊΟ ₂ 30.28; A1 ₂ O ₃ 2.68; Re ₂ O ₃ 2.75; CaO 57.8; P ₂ O1,7; other4,7.

The method is as follows. 20

Example 1. 60 g of nepheline sludge with chemical composition,%: 5U ₂ 30.28; A1 ₂ O ₃ , 2.68; Re ₂ O ₃ 2.75; CaO 57.8; K ₂ O 1.7; other 4.7, treated with 240 ml of potash soda solution with a concentration of K ₂ CO ₃ 312 g / l 25 and № ₂ 0καρΓ 50.1 g / l. with content in it

7.2 g / l K ₂ Pick at W: T = 5: 1 and 140 ° C for 15 min in a stirred reactor.

The resulting slurry is filtered and the precipitate is washed. thirty

- The chemical composition of the filtrate, g / l 8 5ίΟ ₂ 20.67; K ₂ Otss' of 106.72; 1Ma ₂ Onorb 51.6; Κ-2θκορί) Ю7,65.

The chemical composition of the precipitate,%: 5ίΟ ₂ 20,05; A1 ₂ O ₃ 2.27; Re ₂ O ₃ 2.37; ₃₅

CaO 51.68; P ₂ O 1.1; other 2.24; np 20.32. A precipitate of 68.5 was obtained in terms of dry weight.

Example 2. 60 g of nepheline sludge 40 are treated with 200 ml of potash soda solution with a concentration of K ₂ CO ₃ 480 g / l and No. ₂ O _ka r ({

70.3 g / l with a content of K ₂ O _ka at _ST Yu, 1 g / l at. W: T = 4.5: 1 and 150 ° C for 60 minutes in a stirred reactor. 45

The resulting slurry is filtered and the precipitate is washed.

The chemical composition of the obtained filtrate, g / l: K ₂ Ok _P p5207,6; K ₂ 6kAust 121.3; Ma ₂ 0cart5 • 72.21; 5ϊΟ ₂ 28.25. ' 50

The chemical composition of the precipitate obtained,%: δϊθ ₂ 18.2; A1 ₂ O ₃ 2.31; Re ₂ O ₃ 2.29; CaO 51.24; B ₂ O 1.09; other 1.94; ppt 22.3.

A precipitate of 69 g was obtained in terms of dry weight. 55

Example 3. 60 g of nepheline sludge are treated with 205 ml of potash soda solution with a concentration of K ₂ CO ₃ 402 g / l and No. ₂ 0καρί 60.3 g / l with a content of K ₂ O in it _to acst 9.5 g / l with W: T = 4.5: 1 and 120 ° C for 90 minutes.

The resulting slurry is filtered, the precipitate is washed.

The chemical composition of the obtained filtrate, g / l: K ₂ O _YO p ^ 165.3; K ₂ O _I (X (.st 111.4;

^No. 2 ° καρ £ ⁶² >⁴; θ '° 2 26.95.

The chemical composition of the precipitate obtained,%: WL ₂ 18.9; A1 ₂ O ₃ 2.19; Re ₂ O ₃ 2.36; CaO 53.1; K ₂ O 1.21; other 2.36; ppt 19.8.

A precipitate of 67.0 g was obtained, calculated on the dry

weight.

Using the proposed method of hydrochemical treatment of nepheline sludge allows to intensify the process, as well as more efficient use of nepheline sludge, thereby increasing the economic efficiency of the production of alumina from nepheline concentrate. Simultaneously with the production of a one-component raw mix for cement production with a molecular content of CaO / 8U ₂ = 1.8, potash soda solution is caustified until the content of H ₂ O c ^ st 100-120 g / l, which is reused in the hydrochemical processing of nepheline concentrate to obtain sodium metasilicate, potash-silica mixture, silica.

With a decrease in the amount of silica in the initial mixture, the consumption of limestone decreases, the yield of alkali increases to 92–95%.

A concentrated solution of silica (60-75 g / l) is used to obtain silicate products. .

In the production of 1 ton of alumina is formed

5.5 tons of nepheline sludge, while consuming 6.9 tons of limestone for alumina production and 5.5 tons for cement production.

It produces 0.7 tons of soda, calcined potash 0.22 tons and Portland cement 9. tons.

During the hydrochemical treatment of nepheline sludge, a one-component mixture is obtained and, thus, excludes the use of 5 5.5 tons of limestone.

Claims (1)

Claim The method of hydrochemical treatment of nepheline sludge with an alkaline solution, characterized in that, in order to intensify the process, nepheline sludge is treated with potash soda solution with a concentration of K ₂ CO ₃ 300-480 g / l № ₂ О 85-120 g / l with 5 916464 W: T = (4.5–5): 1 at 120–150 ° C for 15–50 ° C for 15–90 min.