Method for recycling and using medium chrome yellow production wastewater

A production process, waste water recycling technology, applied in chemical instruments and methods, neutralizing water/sewage treatment, water pollutants, etc., to achieve the effect of no secondary pollution, mild reaction conditions, and reduced emissions

Inactive Publication Date: 2017-08-04
HUBEI ZHENHUA CHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a method for comprehensively utilizing medium chrome yellow production process wastewater with simple process, low e

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0033] Take 2L of waste water produced in the production process of chrome yellow, add liquid alkali to adjust the pH value to 7.5, lead ions will form 42g of white precipitate with lead hydroxide. After filtration, the lead hydroxide is dissolved with nitric acid and returned to use as the raw material of lead chromate. The filtrate is adsorbed by the resin column, and the clear liquid is heated to 100°C, stirred and evaporated. After a large amount of white sodium nitrate crystals were produced, the temperature was lowered to 25°C, and 80 g of sodium nitrate crystals and 150 ml of crystallization liquid were separated by filtration. The crystallization liquid and the supernatant liquid were mixed at a ratio of 1:2 and then evaporated and crystallized.

example 2

[0035] Take 2L of waste water produced in the production process of chrome yellow, add liquid alkali to adjust the pH value to 8.5, lead ions will form 42g of white precipitate with lead hydroxide. After filtration, the lead hydroxide is dissolved with nitric acid and returned to use as the raw material of lead chromate. The filtrate is adsorbed by the resin column, and the clear liquid is heated to 95°C, stirred and evaporated. After a large amount of white sodium nitrate crystals are produced, the temperature is lowered to 20°C, and 100 g of sodium nitrate crystals and 100 ml of crystallization solution are separated by filtration. The crystallization solution and the clear solution were mixed at a ratio of 1:1.5 and then evaporated and crystallized.

example 3

[0037] Take 3L of waste water produced in the production process of chrome yellow, add liquid alkali to adjust the pH value to 8.0, lead ions will form 63g of white precipitate with lead hydroxide. After filtration, the lead hydroxide is dissolved with nitric acid and returned to use as the raw material of lead chromate. The filtrate is adsorbed by the resin column, and the clear liquid is heated to 97°C, stirred and evaporated. After a large amount of white sodium nitrate crystals are produced, the temperature is lowered to 35° C., and 140 g of sodium nitrate crystals and 200 ml of crystallization solution are separated by filtration. The crystallization liquid and the supernatant liquid were mixed at a ratio of 1:3 and then evaporated and crystallized.

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PUM

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Abstract

The invention discloses a method for recycling and using medium chrome yellow production wastewater. The method comprises the following steps: adding sodium hydroxide into medium chrome yellow production wastewater so as to adjust the pH value to 7-9, and precipitating, so as to separate Pb<2+>; carrying out evaporative crystallization on obtained filtrate, so as to separate out sodium nitrate crystals; cooling, so as to further separate out the sodium nitrate crystals; and filtering, and separating, so as to obtain the sodium nitrate crystals and a crystallization solution. The crystallization solution returns to an evaporative crystallization operation stage, the volume ratio of the crystallization solution to the filtrate is 1 to (1-3); and an obtained lead hydroxide precipitate reacts with nitric acid to generate lead nitrate, and lead nitrate is taken as one of the raw materials of a medium chrome yellow production process. The efficient and comprehensive resource utilization of medium chrome yellow process wastewater is realized, the discharging of wastewater is reduced, and a sodium nitrate product is produced, so that the method has an environmental protection benefit, and the economic benefit is increased; and a low-temperature distillation method is simple in process, reaction conditions are mild, new substances are not introduced, and secondary pollution is avoided.

Description

technical field [0001] The invention belongs to the technical field of inorganic salt industry, and in particular relates to a method for recycling medium chrome yellow production process wastewater. Background technique [0002] Chromate pigments have excellent pigment quality and anti-corrosion properties, and are widely used in the production of paints and inks, as well as in pigments and rubber coloring. There are more than 10 categories and more than 20 varieties of chromate pigments produced in my country, such as lead chrome yellow and lead chrome orange. [0003] Medium chrome yellow, also known as pigment yellow 34. Pigments whose main component is lead chromate, whose chemical composition is PbCrO 4 , the content is about 90%~94%, the appearance is light red yellow powder, monoclinic crystal form, density 5.1~6.0g / cm3, oil absorption 13~27g / 100g, excellent color bleeding resistance, bright color, Strong tinting power; low density, non-toxic. Mainly used in coat...

Claims

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Application Information

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IPC IPC(8): C02F9/10C01D9/16
CPCC02F9/00C01D9/16C02F1/001C02F1/04C02F1/66C02F2101/308
Inventor 王欢刘静文周飞龙吴德红蔡再华石义朗程西川黄国强
Owner HUBEI ZHENHUA CHEMICAL CO LTD
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