The enhancement effect of pre-reduction using zero-valent iron on the solidification of chromite ore processing residue by blast furnace slag and calcium hydroxide.
A bench scale study was performed to assess the effectiveness of the solidification of chromite ore processing residue (COPR) by blast furnace slag and calcium hydroxide, and investigate the enhancement effect of pre-reduction using zero-valent iron (ZVI) on the solidification treatment. The degree of Cr immobilization was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) as well as the solid waste-extraction procedure for leaching toxicity-sulfuric acid & nitric acid method (Chinese standard HJ/T299-2007). Strength tests and semi-dynamic leaching tests were implemented to investigate the potential for reusing the final treatment product as a readily available construction material. The experimental results showed that the performance of pre-reduction/solidification (S/S) was superior to that of solidification alone. After pre-reduction, all of the S/S treated COPR samples met the TCLP limit for total Cr (5 mg L(-1)), whereas the samples with a COPR content below 40% met the pollution control limit of bricks and building block products (Chinese standard HJ/T 301-2007) produced with COPR for total Cr (0.3 mg L(-1)). At the same time, all of the S/S treated specimens tested were suitable for utilization at certain levels.
State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
Jinchunzi
J
Li
State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
Zhonglin
Z
Chen
State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. Electronic address: shenjimin@hit.edu.cn.
Jimin
J
Shen
State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
Binyuan
B
Wang
State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
Leitao
L
Fan
D000497:Alloys / Q000737:chemistry; D002126:Calcium Hydroxide / Q000737:chemistry*; D002681:China; D002857:Chromium / Q000737:chemistry*; D019245:Compressive Strength; D003252:Construction Materials; D052918:Environmental Restoration and Remediation; D007220:Industrial Waste / Q000032:analysis*; D007221:Industry; D007501:Iron / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D017942:Nitric Acid / Q000737:chemistry; D011312:Pressure; D013464:Sulfuric Acids / Q000737:chemistry; D014961:X-Ray Diffraction
D000497:Alloys; D007220:Industrial Waste; D008670:Metals; D013464:Sulfuric Acids; D002857:Chromium; D017942:Nitric Acid; D007501:Iron; C033158:sulfuric acid; D002126:Calcium Hydroxide
Blast furnace slag–calcium hydroxide; COPR; Pre-reduction/solidification; ZVI