Method for treating acid wastewater of titanium white

A technology for acid wastewater and pretreatment, applied in the direction of neutralization water/sewage treatment, etc., which can solve the problems of low lime utilization rate, high production cost, and large consumption, so as to improve lime utilization rate, eliminate secondary pollution, and reduce treatment cost effect

Active Publication Date: 2009-12-30
ANHUI ANNADA TITANIUM IND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The technological process is mature and reliable, and domestic and foreign sulfuric acid titanium dioxide production enterprises basically use this method to treat acid wastewater, but there are disadvantages of low utilization rate of raw lime, large consumption, and high production cost; at the same time, lime digested residue is produced, causing secondary pollution
Especially in areas where high-quality quicklime is in short supply, the shortcomings of this process are more obvious and prominent

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] Eliminate the residual lime slag (the main component is CaCO 3 , Also contains some lime and Ca(OH) 2 ), use a ball mill wet grinding method to reach 90% over 100 mesh slurry. The total CaO content in the slurry is 21.0%, and the effective CaO content is 9.6%. Take 500.0 grams of titanium white acid wastewater, add 24.0 grams of the above slurry, and mechanically stir for 5-10 minutes. The pH value of the acid wastewater rises from less than 0.5 to 4.0. After filtration, 33.7 g of white gypsum containing 21.36% water was obtained. The filtrate is neutralized with milk of lime, the total content of CaO in the milk of lime is 27.6%, and the effective content of CaO is 26.9%. Add 7.0 g of lime milk, mechanically stir and aerate for 20-40 minutes, and neutralize the filtrate to a pH of 7.2. After filtration, 33.2 g of red gypsum containing 66.34% water was obtained.

Embodiment 2

[0013] Eliminate the residual lime slag in the chemical kiln (the main component is CaCO 3 , Also contains some lime and Ca(OH) 2 ), the slurry is wet-milled to 90% over 60 mesh by a ball mill. The total CaO content of the slurry is 21.0% and the effective CaO content is 9.6%. Take 500.0 grams of titanium white acid wastewater, add 24.3 grams of the above slurry, and mechanically stir for 5-10 minutes. The pH value of the acid wastewater rises from less than 0.5 to 2.0. Without filtering, the lime milk is directly used to continue neutralization. The total CaO content of the lime milk is 27.6% and the effective content of CaO is 26.9%. Add 7.4 grams of lime milk, mechanically stir and aerate for 20-40 minutes, and neutralize the filtrate to a pH of 7.3. After filtration, 69.4 g of red gypsum containing 56.34% water content was obtained.

Embodiment 3

[0015] Take 500.0 grams of titanium dioxide acid wastewater and add calcite powder (main component CaCO 3 The content of 99%, 90% over 80 mesh) 9.66 g, mechanical stirring for 5-10 minutes, the PH value of the acidic wastewater rises from less than 0.5 to 3.0. After filtration, 24.5 g of 23.36% water-containing white gypsum was obtained. The filtrate is neutralized with milk of lime. The total CaO content of the milk of lime is 27.6% and the effective CaO content is 26.9%. Add 7.0 g of lime milk, mechanically stir and aerate for 20-40 minutes, and neutralize the filtrate to a pH of 7.2. After filtration, 43.4 g of red gypsum containing 63.54% water was obtained.

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Abstract

This invention discloses a method for treating acidic wastewater produced during titanium dioxide production by H2SO4 method by using quicklime. The method comprises: wet-grinding quicklime digestion dreg into 60 mesh slurry (90%), and pre-neutralizing the acidic wastewater of titanium dioxide with the slurry. The method has such advantages as high quicklime utility, and no secondary pollution.

Description

Technical field [0001] The invention relates to a method for treating acid waste water, in particular to a method for treating acid waste water in the production of sulfuric acid titanium dioxide by using quicklime raw materials. Background technique [0002] The production process of sulfuric acid titanium dioxide is characterized by large discharge of waste residue, waste water and exhaust gas, and serious pollution. For acid wastewater alone, there are 100 to 150 tons per ton of titanium dioxide produced. Since the acidic wastewater contains a large amount of free sulfuric acid (1.0-3.0% by weight) and iron (0.1-0.5% by weight) and other harmful impurities, it must be treated before it can be discharged. [0003] The traditional titanium dioxide acidic wastewater treatment process is that quicklime is first digested into lime milk, then neutralized with acidic wastewater to neutrality, and then fully aerated and oxidized, and the gypsum residue and water are separated by preci...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C02F1/66
Inventor 杨文斌叶丽君鲁军
Owner ANHUI ANNADA TITANIUM IND CO LTD
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