CN110255770B - Method for treating arsenic in nonferrous smelting waste acid by using jarosite slag and carbide slag - Google Patents

Abstract

The invention relates to a method for treating arsenic in nonferrous smelting waste acid by using jarosite slag and carbide slag, belonging to the technical field of heavy metal pollution treatment. The invention mixes the jarosite slag and the carbide slag evenly, and ball-mills the mixture until the granularity of the mixture is not higher than 0.56 μm to obtain mixed slag powder; adding the mixed slag powder and potassium permanganate into the waste acid, uniformly mixing, continuously introducing air under the stirring condition, and performing oxidation dearsenification reaction for 24-36 hours to obtain a solid-liquid mixture; solid-liquid separation is carried out on the solid-liquid mixture to obtain arsenic-containing solid and filtrate, the arsenic-containing solid is stockpiled and treated, and the filtrate is subjected to the next step of deep arsenic removal treatment. The method adopts the jarosite slag and the carbide slag to remove arsenic in the waste acid, has excellent arsenic removal effect, simple process operation and low production cost, generates less sludge after arsenic removal, and relieves the problem of large sludge stockpiling amount.

Description

A method for treating arsenic in non-ferrous smelting polluted acid with jarosite slag and carbide slag

technical field

The invention relates to a method for treating arsenic in polluted acid of non-ferrous smelting with jarosite slag and calcium carbide slag, and belongs to the technical field of heavy metal pollution control.

Background technique

The jarosite method was developed in the 1960s after years of experimental research at the Reston Electric Zinc Plant of the Australian Electric Zinc Company, and is widely used in zinc smelting. my country is a big country of zinc production and consumption. More than 50% of zinc smelters use the jarosite method to remove iron. This method will produce a large amount of jarosite slag in the process of smelting zinc, and the annual slag production is about the output of zinc. half of . These waste residues are generally stored directly without proper treatment, causing great harm to the surrounding environment. The main elements of jarosite slag are Fe, S, Zn, and also contain As, Cd, Ga, In, and other elements, and the Fe content is generally about 20~30%. The main phases of the jarosite slag are KFe ₃ (SO ₄ ) ₂ (OH) ₆ , ZnFe ₂ O ₄ , and Zn ₂ SiO ₄ . As a big country producing zinc in the world, even though the annual discharge of jarosite slag is very large, its utilization rate is very small.

Carbide slag is a by-product of the hydrolysis reaction of calcium carbide in the process of preparing acetylene by the calcium carbide method. The main component of carbide slag is Ca(OH) ₂ , and the remaining components are derived from impurities brought into lime and coke, mainly oxides of Si, Al, Fe, and Mg. Chlorine and alkali content is high.

For the treatment of polluted acid, the most widely used method is the sulfidation method-lime iron salt method. Although this method is simple in process and low in disposal cost, its harmless disposal in practical applications is not complete, and the amount of secondary hazardous waste residues big. A large amount of difficult-to-treat and difficult-to-stack waste residues is stored in the environment, which not only easily releases toxic elements to pollute the environment, but also causes high hardness of the treated water, which is difficult to recycle, and the processing cost of waste residues is expensive.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the prior art, the present invention provides a method for treating arsenic in non-ferrous smelting polluted acid with jarosite slag and calcium carbide slag. The stockpiling of sludge in the process of sewage acid treatment achieves the effect of treating waste with waste, and the process operation is simple, the production cost is low, and it has a broad market prospect.

A method for treating arsenic in non-ferrous smelting polluted acid with jarosite slag and carbide slag, the specific steps are as follows:

(1) Mix the jarosite slag and carbide slag uniformly, and then ball-mill the mixture until the particle size of the mixture is not higher than 0.56 μm to obtain mixed slag powder;

(2) adding the mixed slag powder and potassium permanganate in step (1) into the polluted acid and mixing evenly, continuously introducing air under stirring conditions, and oxidizing and removing arsenic for 24-36 hours to obtain a solid-liquid mixture;

(3) Step (2) Solid-liquid separation of the solid-liquid mixture to obtain arsenic-containing solids and filtrate, the arsenic-containing solids are stored for treatment, and the filtrate enters the next step for deep arsenic removal treatment.

The mass ratio of the step (1) jarosite slag and carbide slag is (10:1)～(13:4).

In the step (2), the solid-liquid ratio g:g:L of the mixed slag powder, potassium permanganate and dirty acid is (8:0.8:1)～(11:1:3).

In the step (2), the stirring speed is 180-200 r/min.

In the step (2), the air flow is 0.5-1 m ³ /h.

The beneficial effects of the present invention are:

(1) The present invention utilizes low-cost jarosite slag to synergize with calcium carbide slag to remove arsenic, which can reduce the amount of sludge in the process of fouling acid treatment, and achieve the effect of treating waste with waste;

(2) jarosite slag belongs to the solid waste slag after zinc smelting, and calcium carbide slag belongs to the residual solid waste after preparing acetylene by the calcium carbide method. In the prior art, the problems of land occupation and management costs for the stockpiling and management of jarosite slag and carbide slag have solved the problems of large amount of waste residue, poor stability and easy toxicity leaching from lime-iron salt treatment of foul acid. ;

(3) The present invention uses jarosite slag to synergize with calcium carbide slag to treat polluted acid, has simple process operation, low production cost, and has a broad market prospect.

Detailed ways

The present invention will be further described in detail below with reference to the specific embodiments, but the protection scope of the present invention is not limited to the content.

Embodiment 1: The jarosite slag composition of the present embodiment is shown in Table 1, and the calcium carbide slag composition is shown in Table 2, and the polluted acid comes from the sulfuric acid workshop of a certain zinc smelter in the southwest region. The main components of foul acid with impurities such as arsenic are shown in Table 3;

Table 1 jarosite slag composition

Table 2 Carbide slag composition

Table 3 Pollution acid composition

A method for treating arsenic in non-ferrous smelting polluted acid with jarosite slag and carbide slag, the specific steps are as follows:

(1) Mix jarosite slag and carbide slag uniformly, and then ball-mill the mixture until the particle size of the mixture is not higher than 0.56 μm to obtain mixed slag powder; wherein the mass ratio of jarosite slag and carbide slag is 10:1, and the ball mill The rotating speed of the machine is 760r/min, and the grinding time is 8min;

(2) Add the mixed slag powder and potassium permanganate in the step (1) to the polluted acid and mix them evenly. Under stirring conditions, air is continuously introduced and the oxidative and dearsenic reaction is carried out for 24 hours to obtain a solid-liquid mixture; wherein the mixed slag powder, high manganese The solid-liquid ratio g:g:L of potassium acid and polluted acid is 8:0.8:1, the stirring speed is 180r/min, and the air flow is 0.5m ³ /h;

(3) Step (2) Solid-liquid separation of the solid-liquid mixture to obtain arsenic-containing solids and filtrate, arsenic-containing solids are stored for treatment, and the filtrate enters the next step for deep arsenic removal treatment;

The toxicity leaching test of arsenic-containing solids was carried out according to the U.S.EPA "Method 1311-toxicity Characterisitic Leaching Procedure" provided by the US Environmental Protection Agency. The toxicity test results are shown in Table 4.

Table 4 Toxicity leaching results of arsenic-containing solids

The filtrate composition is shown in Table 5;

Table 5 Filtrate composition

The arsenic content in the filtrate of this example is 124.1 mg/L, and the removal rate of arsenic is 97.8%.

Embodiment 2: the jarosite slag composition of the present embodiment is shown in Table 6, and the calcium carbide slag composition is shown in Table 7, and the polluted acid comes from the sulfuric acid workshop of a certain zinc smelter in the southwest region and produces after washing the smelting flue gas, which contains a large amount of The main components of foul acid with impurities such as arsenic are shown in Table 8;

Table 6 jarosite slag composition

Table 7 Carbide slag composition

Table 8 Pollution acid composition

A method for treating arsenic in non-ferrous smelting polluted acid with jarosite slag and carbide slag, the specific steps are as follows:

(1) Mix the jarosite slag and the carbide slag evenly, and then ball-mill the mixture until the particle size of the mixture is not higher than 0.47 μm to obtain the mixed slag powder; the mass ratio of the jarosite slag and the carbide slag is 13:4, and the ball mill The rotating speed of the machine is 910r/min, and the grinding time is 11min;

(2) Add the mixed slag powder and potassium permanganate in step (1) to the polluted acid and mix them evenly, continue to introduce air under stirring conditions and conduct oxidation and dearsenic reaction for 36 hours to obtain a solid-liquid mixture; among which the mixed slag powder, high manganese The solid-liquid ratio g:g:L of potassium acid and polluted acid is 11:1:3, the stirring speed is 200r/min, and the air flow is 0.8m ³ /h;

(3) Step (2) Solid-liquid separation of the solid-liquid mixture to obtain arsenic-containing solids and filtrate, arsenic-containing solids are stored for treatment, and the filtrate enters the next step for deep arsenic removal treatment;

The toxicity leaching test of arsenic-containing solids was carried out according to the U.S.EPA "Method 1311-toxicity Characterisitic Leaching Procedure" provided by the U.S. Environmental Protection Agency. The toxicity test results are shown in Table 9.

Table 9 Toxicity leaching results of arsenic-containing solids

The filtrate composition is shown in Table 10;

Table 10 Filtrate composition

The arsenic content in the filtrate of the present embodiment is 254.5 mg/L, and the removal rate of arsenic is 97.5%.

Embodiment 3: The jarosite slag composition of the present embodiment is shown in Table 11, and the calcium carbide slag composition is shown in Table 12, and the polluted acid comes from the sulfuric acid workshop of a zinc smelter in the southwest region, and the smelting flue gas is washed and produced containing a large amount of water. Foul acid with impurities such as arsenic, the main components are shown in Table 13;

Table 11 jarosite slag composition

Table 12 Carbide slag composition

Table 13 Pollution acid composition

A method for treating arsenic in non-ferrous smelting polluted acid with jarosite slag and carbide slag, the specific steps are as follows:

(1) Mix jarosite slag and carbide slag uniformly, and then ball-mill the mixture until the particle size of the mixture is not higher than 0.42 μm to obtain mixed slag powder; wherein the mass ratio of jarosite slag and carbide slag is 11:2, and the ball mill The rotating speed of the machine is 835r/min, and the grinding time is 9.5min;

(2) Add the mixed slag powder and potassium permanganate in step (1) into the polluted acid and mix them evenly. Under stirring conditions, the air is continuously introduced and the oxidative and dearsenic reaction is carried out for 30 hours to obtain a solid-liquid mixture; wherein the mixed slag powder, high manganese The solid-liquid ratio g:g:L of potassium acid and polluted acid is 9:0.9:2, the stirring speed is 190r/min, and the air flow is 1m ³ /h;

(3) Step (2) Solid-liquid separation of the solid-liquid mixture to obtain arsenic-containing solids and filtrate, arsenic-containing solids are stored for treatment, and the filtrate enters the next step for deep arsenic removal treatment;

The toxicity leaching test of arsenic-containing solids was carried out according to the U.S.EPA "Method 1311-toxicity Characterisitic Leaching Procedure" provided by the U.S. Environmental Protection Agency. The toxicity test results are shown in Table 14.

Table 14 Toxicity leaching results of arsenic-containing solids

The filtrate composition is shown in Table 15;

Table 15 Filtrate composition

The arsenic content in the filtrate of this example was 298.3 mg/L, and the arsenic removal rate was 97.7%.

Claims (2)

1. a method for arsenic in non-ferrous smelting polluted acid processing with jarosite slag in conjunction with carbide slag, is characterized in that, concrete steps are as follows: (1) Mix the jarosite slag and the carbide slag uniformly, and then ball-mill the mixture until the particle size of the mixture is not higher than 0.56 μm to obtain the mixed slag powder; the mass ratio of the jarosite slag to the carbide slag is (10:1) ~(13:4); (2) Add the mixed slag powder and potassium permanganate in the step (1) to the polluted acid and mix them evenly. Under stirring conditions, air is continuously introduced and the oxidative dearsenic reaction is carried out for 24-36 hours to obtain a solid-liquid mixture; wherein the mixed slag powder, The solid-liquid ratio g:g:L of potassium permanganate and polluted acid is (8:0.8:1)~(11:1:3), and the air flow is 0.5~1m ³ /h; (3) Step (2) Solid-liquid separation of the solid-liquid mixture to obtain arsenic-containing solids and filtrate, the arsenic-containing solids are stored for treatment, and the filtrate enters the next step for deep arsenic removal treatment. 2. The method for treating arsenic in non-ferrous smelting polluted acid with jarosite slag and calcium carbide slag according to claim 1, characterized in that: the stirring speed of step (2) is 180～200r/min.