Method for preparing polyferric chloride by using wastewater produced in pickling of steel with hydrochloric acid

A technology for polymerizing ferric chloride and pickling wastewater, applied in the field of coking, can solve problems such as high price and toxicity, and achieve the effects of simple production operation, simple process reaction process and high concentration

Inactive Publication Date: 2019-01-22
ANGANG STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the polymerization oxidant chlorates used in this method are flammable and explosive chemicals, toxic and expensive, and production and procurement will be regulated. Therefore, it is necessary to find safe raw material medicaments, sufficient supply, and low-cost and high-efficiency. alternative method

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] The method for preparing polyferric chloride with iron and steel hydrochloric acid pickling waste water comprises the following steps:

[0025] 1) Pretreatment of raw hydrochloric acid pickling wastewater: steam heating and concentration at 70°C to 100°C to increase the concentration of ferrous chloride;

[0026] 2) Add a small amount of hydrochloric acid and iron-containing substances to the concentrated hydrochloric acid pickling wastewater, adjust the hydrochloric acid pickling wastewater so that its pH value is 1 to 2, and the total iron weight percentage content is more than 10%. The specific gravity of pickling wastewater ≥ 1.2g / cm 3 ;

[0027] 3) Feed the filtered hydrochloric acid pickling wastewater quantitatively into the reactor, add phosphate buffer in batches, add 0.03t to 0.04t of phosphate buffer per ton of concentrated hydrochloric acid pickling wastewater, and stir fully to make it Completely dissolve, and add oxidant under the condition of stirring a...

Embodiment 2

[0030] The method for preparing polyferric chloride with iron and steel hydrochloric acid pickling waste water comprises the following steps:

[0031] 1) Add iron-containing substances to the hydrochloric acid pickling wastewater according to the mass ratio of 1:0.06 to 1:0.09 to the hydrochloric acid pickling wastewater, and react at room temperature for 10-30 minutes to fully react the iron-containing substances with the pickling wastewater, adjust The specific gravity of wastewater is 0.9~1.0g / cm 3 , the pH value is 5-6;

[0032] 2) The fully reacted hydrochloric acid pickling wastewater is sent to the distillation process, the distillation temperature is set at 70° C. to 100° C., the distilled water recovery rate reaches more than 90%, and the remaining concentrated wastewater is used as a raw material for preparing polyferric chloride.

[0033] 3) When preparing polyferric chloride, the concentrated wastewater obtained in step 2) is filtered; the filtered hydrochloric ac...

Embodiment 3

[0036] Measure 1100ml of iron and steel hydrochloric acid pickling waste liquid, and concentrate it by steam heating at 85°C to obtain 175ml with a specific gravity of 1.2g / cm 3 The concentrated waste liquid, its pH value is 1, the raw material is filtered and moved into a four-necked bottle, and 5.4g of potassium dihydrogen phosphate is weighed as a buffer, added in 4 times to fully dissolve the buffer, and set 45 under strong stirring conditions ℃ constant temperature, pass into the concentrated waste liquid ozone concentration of 120mg / L, the dose is 150mg / h, after oxidative polymerization for 4 hours, a stable polymerized ferric chloride product can be obtained.

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PUM

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Abstract

The invention relates to a method for preparing polyferric chloride by using wastewater produced in pickling of steel with hydrochloric acid. The method comprises the following steps: pretreating hydrochloric acid pickling wastewater, and quantitatively feeding the filtered hydrochloric acid pickling wastewater into a reaction kettle; adding a phosphate buffer in batches, wherein 0.03 to 0.04 tonof the phosphate buffer is added for per ton of the concentrated hydrochloric acid pickling wastewater; carrying out sufficient stirring to completely dissolve the phosphate buffer; and adding an oxidizing agent under the conditions of stirring and constant-temperature heating for an oxidative polymerization reaction, wherein the concentration of the oxidizing agent is 120-150 mg/L, 0.7 to 1.1 kg/h of the oxidizing agent is added for per ton of the concentrated hydrochloric acid pickling wastewater, the rotating speed of an agitator in a reaction vessel is 200 to 400 rpm, a reaction temperature is 40 to 60 DEG C, and after sufficient reaction for 14 to 26 h, the polyferric chloride is obtained. The method has the following advantages: process flow is simple; only one reaction kettle is needed in a core production procedure; and the oxidative polymerization reaction is implemented in the reaction kettle.

Description

technical field [0001] The invention belongs to the technical field of coking, and in particular relates to a method for preparing polyferric chloride by using iron and steel hydrochloric acid pickling wastewater. Background technique [0002] In the process of steel processing, degreasing and descaling treatment is required before steel cold rolling or steel surface coating, and hydrochloric acid surface pickling is often used, which will form a large amount of acidic wastewater containing iron ions. For this kind of acidic wastewater, the conventional practice is to build a neutralization wastewater station to meet the environmental protection discharge standards and achieve standard discharge. From the perspective of resource reuse, steel hydrochloric acid pickling wastewater can be used to prepare polyferric chloride, and polyferric chloride can be used as a flocculant for sewage treatment. [0003] In the prior art, Patent Publication No. CN1266819A discloses a method ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G49/10C02F1/52
CPCC01G49/10C02F1/5245
Inventor 薛占强王丽英穆春丰张大奎张展
Owner ANGANG STEEL CO LTD
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