Unlock instant, AI-driven research and patent intelligence for your innovation.

Chromium slag high-temperature detoxification method

A chromium slag and high temperature technology, applied in the field of solid waste disposal, can solve the problems of strict reduction conditions and low reduction efficiency, and achieve the effect of simple components, fast reaction speed and remarkable detoxification effect

Inactive Publication Date: 2018-02-13
CHANGZHOU UNIV
View PDF5 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the high-temperature carbon reduction method is widely used, but this method has problems such as strict requirements for reduction conditions and low reduction efficiency.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0016] The laboratory simulates the detoxification process of chromium slag and analyzes the pure reagent Cr 2 o 3 The mixed material composed of CaO (n(Ca) / n(Cr)=1) was mixed with a ball mill for 30 minutes. The clinker obtained by calcining the mixed material at 1000°C for 1 hour to simulate the calcification and roasting of chromite is the simulated chromium slag. The Cr(III) oxidation rate of the calcined material was detected by the leaching test to be 16%, and the hexavalent chromium in the leaching solution far exceeded the national standard for hazardous waste identification.

[0017] According to the additive provided by the present invention, the component of selecting additive is m(H 3 BO 3 ):m(NH 4 B4O 7 ):m(NH 4 B 5 o 8 )=40:30:30, mix the additive and the simulated chromium slag through a ball mill for 10 minutes, and the amount of the additive is to ensure that n(B) / n(Cr(VI))=2.5 in the mixed material. The mixed material was treated at high temperature ...

example 2

[0019] According to the additive provided by the present invention, the component of selecting additive is m(H 3 BO 3 ): m(NH 4 B4O 7 ):m(NH 4 B 5 o 8 )=60:20:20, mix the additive and the simulated chromium slag through a ball mill for 10 minutes, and the amount of the additive is to ensure that n(B) / n(Cr(VI))=2 in the mixed material. The mixed material was treated at high temperature in a muffle furnace for 1 hour, the heating rate of the muffle furnace was 5°C / min, and the processing temperature was 1000°C. The toxicity of hexavalent chromium in chromium slag was detected by using the leaching method provided in the "Hazardous Waste Identification Standard Leaching-Toxic Identification". L, meet the requirements of detoxification.

example 3

[0021] According to the additive provided by the present invention, the component of the selected additive is NH 4 B 4 o 7 , mix the additive and the simulated chromium slag through a ball mill for 10 minutes, and the amount of the additive is to ensure that n(B) / n(Cr(VI))=3 in the mixed material. The mixed material was treated at high temperature in a muffle furnace for 1.5 hours. The heating rate of the muffle furnace was 5°C / min, and the treatment temperature was 1000°C. The toxicity of hexavalent chromium in the chromium slag was detected by using the leaching method provided in the "Hazardous Waste Identification Standard Leaching-Toxic Identification". L, meet the requirements of detoxification.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
oxidation rateaaaaaaaaaa
Login to View More

Abstract

The invention relates to a chromium slag high-temperature detoxification method. The method comprises the steps that firstly, an additive is provided and comprises H3BO3, NH4B4O7 and NH4B5O8, and theadditive can be the single one of the components or a mixture of the components in any proportion; secondly, according to the optimal use amount of the additive, the amount ratio n(B) / n(Cr) of B in the added additive to Cr in chromium slag is 2-4; and thirdly, the additive and the chromium slag are mixed and are subjected to dry grinding through a ball grinding mill for 1-2 h, and mixed materialssubjected to dry grinding through the ball grinding mill are subjected to high-temperature treatment in a high-temperature kiln at 1000-1100 DEG C for 1-1.5 h. The obtained chromium slag can completely reach the national solid hazardous waste leaching toxicity identifying standards. Compared with other chromium slag detoxification methods, the chromium slag high-temperature detoxification method provided by the invention has the characteristics that detoxification is thorough, the process is simple, and the reaction is fast and is a chromium slag detoxification method with application prospects.

Description

technical field [0001] The invention relates to the field of solid waste disposal, in particular to a method for detoxifying chromium slag at high temperature. Background technique [0002] Chromium slag is highly toxic solid waste discharged from chromium salt production plants and ferrochrome plants during the production process. When producing chromium salt or metal chromium, chromite, dolomite, soda ash and other raw materials are mixed and finely ground, and then sent to a rotary kiln for roasting at 1000-1200°C to oxidize trivalent chromium to hexavalent chromium. Then the remaining residue after leaching with water is chromium residue. Usually, 10 tons of chromium slag will be discharged for every 1 ton of metal chromium produced. For every 1t of chromium salt produced, 3-5t of chromium slag will be discharged. Since my country is a big producer of chromium salts, the discharge of chromium slag is also relatively large. The annual discharge of chromium slag is abou...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): A62D3/37A62D101/43
Inventor 毛林强汤润之苏鹏张文艺
Owner CHANGZHOU UNIV