Beneficiation Of Chromium Waste By Means Of Magnetic And Gravitational Separation

Archives of Metallurgy and Materials

M. Brożek¹  A. Surowiak¹  A. Jarosiński² 

[1] AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY, DEPARTMENT OF MINERAL PROCESSING AND ENVIRONMENT PROTECTION, AL. MICKIEWICZA 30, 30-065 KRAKOW, POLAND;POLISH ACADEMY OF SCIENCE, 7 WYBICKIEGO STR., 31-261 KRAKOW, POLAND

关键词: Keywords: chromium waste;    waste management;    gravitational concentration;    magnetic separation;   

DOI  :  10.1515/amm-2015-0299

学科分类：金属与冶金

来源: Akademia Gorniczo-Hutnicza im. Stanislawa Staszica / University of Mining and Metallurgy

【 摘 要 】

The paper presents the results of investigations of chromium recovery from the Cr waste mud, originating in the production of sodium dichromate. The differentiation of physical properties of particles of different contents of chromium and magnesium compounds is a premise for the use of physical separation methods. The investigations were performed on 2 waste samples, taken by random from the waste dump. The investigations of magnetic and gravity concentration for sample I and II were made, respectively. The results of screen and float and sink analyses of sample II indicate that it is possible to obtain Cr- and Mg-enriched products by means of a combined method of separation, i.e. hydraulic classification and, next, gravitational concentration on the shaking table. The concept of gravity concentration of the tested chromium waste was verified in the technical scale on multiboard shaking tables. The advantage of these fittings in relation to laboratory conditions is the possibility of separation of discussed waste without previous classification. The longer time of separation on the industrial shaking table as well as the respective amount of water directed to the process together with feed enabled an exact separation of initial material. The obtained concentrate in such conditions contains from 25 to 35% Cr2O3, depending on the chromium content in the initial waste material. It results from the fractional magnetic analysis of sample I that by means of the magnetic separation it is possible to obtain the magnetic concentrate of Cr2O3 content minimum 20% and, simultaneously, to obtain the non-magnetic product of increased MgO content. The optimum separation conditions regarding the yield and content of Cr2O3 were determined. The highest value of criterion K for the grade of the concentrate containing over 20% of Cr2O3 is obtained when the 10 mm diameter balls and the 1150 kA/m magnetic field intensity are applied. The yield of the concentrate equals about 9.5 % and recovery of Cr2O3 almost 22%. In the non-magnetic product the content of Cr2O3 equals 7.74% and MgO 27.36%.

【 授权许可】

Unknown