Resource utilization method for metal surface treatment sludge

A metal surface treatment and recycling technology, applied in metallurgical wastewater treatment, chemical instruments and methods, sludge treatment, etc., can solve the high cost of incineration harmless disposal, low-grade resource utilization, iron nickel chromium manganese recovery Problems such as high cost, achieve considerable economic value, high value of resource recycling, no secondary pollution and waste generation

Inactive Publication Date: 2016-08-24
徐超群 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since the sludge contains a large amount of heavy metal elements, it needs to be managed in accordance with industrial hazardous waste. The direct brick-making disposal method is limited, and the solidified and stabilized disposal method has increased the sludge. The disposal cost is high, and the harmless disposal cost of incineration is high. Heavy metals have been produced for stable and harmless disposal, which is a low-grade resource utilization method
[0005] At present, there are three main ways to deal with these sludges: one is to send them to hazardous waste landfills after solidification and stabilization; the other is to use cement kilns for coordinated incineration and use them as cement fillers; It is mixed with cement to make unburned bricks. Since this sludge is a hazardous waste, its direct use is limited
"A Method for Recycling Heavy Metal Resources from Neutralized Sludge in Stainless Steel Pickling Wastewater" applied by Liu Fuqiang of Nanjing University, patent application number CN201210141865.0, using acid leaching, oxidation, ion exchange, neutralization and precipitatio

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] The sludge is the sludge produced by 200 series stainless steel pickling water treatment, with a moisture content of about 46%. Sludge composition: Fe(OH) 2 14.60%; Cr(OH) 3 4.60%; Ni(OH) 2 0.44%; Mn(OH) 2 1.38%; Cu(OH) 2 0.37%; Calcium sulfate 10.05-12.45%; Calcium fluoride 20.2-22%; Take 1000Kg of the sludge and add it to the reaction tank. It is calculated that the sludge contains 90.8Kg of iron, 23.0Kg of chromium, 2.8Kg of nickel, manganese 8.5Kg, copper 2.4Kg, from the analysis data of the dried sludge composition, the metal sludge content is 21.4%, the insoluble calcium salt sludge content is 30.4-34.5%, add 15% hydrochloric acid solution 1.5m 3 Soak the sludge, wait for the sludge to soften, stir and react for 1 hour, at this time the acidity is about pH=0.5, continue to add this kind of sludge under stirring to neutralize part of the free acid, control the pH=2.0, stop adding the mud, and react 2 Press filter the suspension after 1 hour, and the solid obta...

Embodiment 2

[0025] The sludge is the sludge produced by 200 series and 300 series mixed stainless steel pickling water treatment, with a moisture content of about 68%. Sludge composition: Sludge composition: iron content 5.62%; chromium content 0.53%; nickel content 0.31%; manganese content 0.36%; mixed wet sludge, metal hydroxide accounts for 11.7%, calcium sulfate fluoride The calcium content is 20.3%. Take 1000Kg of the sludge and add it to the reaction tank. After calculation, the sludge contains 56.2Kg of iron, 5.3Kg of chromium, 3.1Kg of nickel, and 3.6Kg of manganese. Add 1.2m of 15% hydrochloric acid solution 3 Soak the sludge, wait for the sludge to soften, stir and react for 1 hour, at this time the acidity is about pH=0.5, continue to add this kind of sludge under stirring, neutralize part of the free acid, control the pH=3.0, stop adding the mud, and react After 1.5 hours, the suspension was press-filtered, the solid was washed with hydrochloric acid of pH=3, and after washing...

Embodiment 3

[0028] The electroplating industrial park sludge is 1000Kg, and the water content is 70%. The solid matter is mainly a mixture of calcium sulfate, calcium phosphate and metal hydroxide. According to elemental analysis, the metal content is about 60-75Kg, and the equivalent amount of metal hydroxide is 92-115Kg. Among 300Kg solids, about 200Kg is insoluble calcium salt sludge, and 100Kg is metal hydroxide sludge. Add 15% hydrochloric acid solution 1.2m 3 Soak the sludge, wait for the sludge to soften, stir and react for 1 hour, at this time the acidity is about pH=0.5, continue to add this kind of sludge under stirring to neutralize part of the free acid, control the pH=3.0, stop adding the mud, react 1.5 Press filter the suspension after 1 hour, wash the solid with hydrochloric acid with pH=3, press filter and wash twice, add lime emulsion to the neutralization tank until the solid is pH=6-9, press filter to get the heavy metal content lower than the national hazard Waste sta...

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PUM

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Abstract

The invention relates to a resource utilization method for metal surface treatment sludge, in particular to resource utilization of stainless steel acid pickling sludge or electroplating sludge, and belongs to sludge pollutant treatment in the steel and metallurgy industry. Hydrochloric acid or nitric acid is adopted as pickle liquor, metal elements in the sludge are acidized and leached, calcium salt sludge hard to dissolve is separated through filter pressing under the condition that the pH is controlled to range from 1.8 to 3.0, the sediment is washed 1-3 times with a diluted hydrochloric acid solution with the pH equal to 3.0+/-0.2, a slightly soluble calcium salt sludge product free of heavy metal pollution is obtained, and the sludge can be used as cement filler or a brickmaking or building material. Furthermore, metal ions in acid leaching filtrate are neutralized with lime emulsion, and a metal hydroxide sludge product is obtained and can be used as a stainless steel smelting material or used for separating single metal elements. Filtrate obtained after metal hydroxide is subjected to filter pressing, and after recycling is carried out 3-5 times, when the concentration of calcium chloride is larger than 20%, evaporation and crystallization are carried out to recycle a calcium chloride product.

Description

technical field [0001] The invention relates to a resource utilization method of metal surface treatment sludge, and more specifically relates to a resource utilization method of stainless steel pickling sludge and electroplating sludge, belonging to the field of industrial waste residue and sludge treatment in the iron and steel and metallurgical industries . Background technique [0002] During the forming and heat treatment process of stainless steel, a layer of black oxide skin will be formed on the surface. This type of oxide skin has a dense structure and strong adhesion to the substrate. It contains Fe, Cr, Ni, a small amount of C and Si, and some products may contain Mn, Ti, Mo, Cu and W and other elements, the oxide structure is: ferrous oxide, iron oxide, ferric oxide, chromium oxide, nickel oxide, silicon dioxide, chromium spinel (Cr 2 o 3 ·FeO) and nickel spinel (NiO·Fe 2 o 3 )Wait. Stainless steel oxide scale not only destroys the aesthetics of the steel su...

Claims

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Application Information

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IPC IPC(8): C02F11/00C01F11/24C02F103/16
Inventor 徐超群陈云华
Owner 徐超群
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