CN100500552C

CN100500552C - Method for treating waste acid produced from titanium dioxide production using vitriol method

Info

Publication number: CN100500552C
Application number: CNB2005101103665A
Authority: CN
Inventors: 张峰; 沈伟祥; 任义生
Original assignee: SHANGHAI MINXIN ENVIRONMENT PROTECTION EQUIPMENT ENGINEERING Co Ltd
Current assignee: SHANGHAI MINXIN ENVIRONMENT PROTECTION EQUIPMENT ENGINEERING Co Ltd
Priority date: 2005-11-15
Filing date: 2005-11-15
Publication date: 2009-06-17
Anticipated expiration: 2025-11-15
Also published as: CN1966400A

Abstract

The invention relates to a way to treat spent acid in the sulfuric acid method to produce titanium pigment. The characteristic of the invention: the method includes the following steps: pulping the spent acid into the sophisticated filtrator through the high pressure anti-corrosion pulp, the filtrate entering the container; the tap water and filtered spent acid going separately into the two inlets of the diffuse dialyzator, separating for the first time the strong H2SO4 from FeSO4 in the permeating solution, the separated strong permeating solution is pulped into the nano-filter membrane to separate H2SO4 for the second time, the content of FeSO4 in the solution is 0.1% or less; the separated permeating solution H2SO4 goes into the reverse osmosis membrane device and the concentrated solution is the dilute sulfuric acid product. The advantage of the invention includes high spent acid recovery rate, high purity, low processing cost and high holding-up rate.

Description

A kind of processing with the method that produces spent acid in the Titanium White Production By Sulfuric Acid Process process

Technical field

The present invention relates to a kind of the processing with the method that produces spent acid in the Titanium White Production By Sulfuric Acid Process process, the spent acid that makes processing belongs to environmental technology field to comprehensive utilization.

Background technology

Nowadays the most development problem that faces with Titanium White Production By Sulfuric Acid Process is the utilization that a large amount of spent acid of producing in the production process can't obtain comprehensive high-efficiency, and then environment polluted, treatment process to this spent acid mainly contains three kinds both at home and abroad: the one, adopt the lime neutralisation, the 2nd, concentration recycle method, the 3rd, diffusive dialysis method.Mainly contain the sulfuric acid about 15%, about 20% ferrous sulfate and micro-titanium valve particulate in the titanium dioxide spent acid.The lime neutralisation is to utilize carbide slag etc. mainly to contain the calcium hydroxide refuse and spent acid carries out acid-base neutralisation, and precipitation is carried out mud-water separation then.The main drawback of this method is: produce a large amount of solid waste, and main sulfur acid calcium, ironic hydroxide and various bits particulate, and sour resource caused waste.The concentration absorption method is to utilize water vapour that spent acid is carried out heating evaporation, removes the part moisture in the spent acid, and cooling is carried out condensing crystal later, and after the solid-liquid separation, concentrated solution returns former technology reuse.The main drawback of this method is: energy consumption is big, the processing cost height.The processing cost that average acid-spending strength per ton doubles is about 1000 yuan.Diffusive dialysis method is to utilize the diffusion dialysis device that spent acid is separated, and produces dialyzate and penetrating fluid, contains ferrous sulfate about 15% and about 5% sulfuric acid in the dialyzate, contains sulfuric acid about 10% and about 5% ferrous sulfate in the penetrating fluid.The main drawback of this method is all to contain sulfuric acid and ferrous sulfate in dialyzate and the penetrating fluid, and penetrating fluid utilizes degree not high.

Summary of the invention

The purpose of this invention is to provide a kind of comprehensive high-efficiency and utilize spent acid, reduce the method for the processing of spent acid environmental pollution with generation spent acid in the Titanium White Production By Sulfuric Acid Process process.

For realizing above purpose, technical scheme of the present invention provides a kind of the processing with the method that produces spent acid in the Titanium White Production By Sulfuric Acid Process process, it is characterized in that, with the filtration of spent acid process, the dialysis that produces in the Titanium White Production By Sulfuric Acid Process process, penetrating fluid enters follow-up reverse osmosis process again and concentrates by nanofiltration, and its method is: the first step. and the accurate filter of spent acid being squeezed into 5um by the high-pressure anticorrosion pump filters, filtrate enters container, and filter residue returns the reuse of titanium white production technology;

Second step. two imports that the spent acid after tap water and the filtration enters the diffusion dialysis device respectively, dominant discharge 0.008-0.012m ³/ d, making the residence time is 8-12 hours, carries out sulfuric acid H ₂SO ₄With ferrous sulfate FeSO ₄The first step separate, separate the penetrating fluid sulfuric acid H that obtains ₂SO ₄The middle ferrous FeSO of sulfur acid ₄Content ratio reach 2-3%;

The 3rd step. the penetrating fluid sulfuric acid H that separation is obtained ₂SO ₄Squeeze into nanofiltration membrane by the high-pressure anticorrosion pump, pump lift is about 100-140 meters, and the flux of nanofiltration membrane is 7-14gfd, carries out sulfuric acid H in the penetrating fluid ₂SO ₄With ferrous sulfate FeSO ₄Second step separate, separate the penetrating fluid sulfuric acid H that obtains ₂SO ₄The middle ferrous FeSO of sulfur acid ₄Content ratio≤0.1%;

The 4th step. will separate the penetrating fluid sulfuric acid (H that obtains for the second time ₂SO ₄) enter reverse osmosis membrane apparatus, carry out reverse osmosis, concentrated solution is the dilute sulphuric acid finished product, and seeing through liquid is pure water, the import of supply diffusion dialysis device.

The present invention utilizes modern membrane technology to handle the titanium dioxide spent acid, and the principal feature of film is exactly to be issued to the purpose of high efficiency separation in the situation of undergoing phase transition not, thereby comprehensive high-efficiency utilizes this spent acid, reduces the pollution of spent acid to environment.

Advantage of the present invention is that spent acid rate of recovery height, purity height, processing costs are low, and the interception capacity height.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Embodiment

The invention will be further described below in conjunction with drawings and Examples.

Embodiment

As shown in Figure 1, be process flow diagram of the present invention, a kind of processing with the method that produces spent acid in the Titanium White Production By Sulfuric Acid Process process, be that the spent acid process that will produce in the Titanium White Production By Sulfuric Acid Process process is filtered, dialysis, dialyzate is by nanofiltration, enter follow-up reverse osmosis process again and concentrate, its method is:

The first step. the accurate filter of spent acid being squeezed into 5um by the high-pressure anticorrosion pump filters, and filtrate enters container, and filter residue returns the reuse of titanium white production technology;

Second step. two imports that the spent acid after tap water and the filtration enters the diffusion dialysis device respectively, dominant discharge 0.01m ³/ d, making the residence time is 8-12 hours, carries out sulfuric acid H ₂SO ₄With ferrous sulfate FeSO ₄The first step separate, separate the penetrating fluid sulfuric acid H that obtains ₂SO ₄The middle ferrous FeSO of sulfur acid ₄Content ratio reach 2-3%;

According to market the demand of low-concentration sulfuric acid (≤30%) is further handled.Concentration is below 15% if desired, and such as the steel surface pre-treatment, second step of nanofiltration membrane is separated the penetrating fluid sulfuric acid H that obtains ₂SO ₄Can directly use; Concentration if desired, then needs such as the surface preparation of copper, zinc at 20%-30%:

The 4th step. will separate the penetrating fluid sulfuric acid H that obtains for the second time ₂SO ₄Enter reverse osmosis membrane apparatus, carry out reverse osmosis, concentrated solution is the dilute sulphuric acid finished product, and seeing through liquid is pure water, and the import of supply diffusion dialysis device sees through molten sulfur acid H by reverse osmosis to nanofiltration membrane ₂SO ₄Concentration is at 20%-30%.

Carry out the first step separation and separate the dialyzate ferrous sulfate FeSO that obtains with second step ₄Sell for iron oxide red manufacturer as the iron oxide red raw material and utilize, employed high-pressure anticorrosion pump, accurate filter, diffusion dialysis device, nanofiltration membrane, reverse osmosis membrane apparatus are bought outside all can be on market in the technology.

Claims

1. handle with the method that produces spent acid in the Titanium White Production By Sulfuric Acid Process process for one kind, it is characterized in that with the filtration of spent acid process, the dialysis that produce in the Titanium White Production By Sulfuric Acid Process process, dialyzate is by nanofiltration, enter follow-up reverse osmosis process again and concentrate, its method is:

The 3rd step. the penetrating fluid sulfuric acid H that separation is obtained ₂SO ₄Squeeze into nanofiltration membrane by the high-pressure anticorrosion pump, pump lift is at 100-140 meters, and the flux of nanofiltration membrane is 7-14gfd, carries out penetrating fluid sulfuric acid H ₂SO ₄With ferrous sulfate FeSO ₄Second step separate, separate the penetrating fluid sulfuric acid H that obtains ₂SO ₄The middle ferrous FeSO of sulfur acid ₄Content ratio≤0.1%;

The 4th step. will separate the penetrating fluid sulfuric acid H that obtains for the second time ₂SO ₄Enter reverse osmosis membrane apparatus, carry out reverse osmosis, concentrated solution is the dilute sulphuric acid finished product, and seeing through liquid is pure water, the import of supply diffusion dialysis device.