Zinc carbonate recovery from brass melting slag

Brass melting slag (20.38 wt.% Zn) was leached in sulfuric acid with concentration of (50 + 80) g/l H2SO4, leaching temperature of (30 + 60) °C for (30 + 120) min. The optimized conditions for 94.16% Zn extraction from brass melting slag were found as 70 g/l H2SO4, room temperature and 90 min. The leaching solution was purified by removal of Fe through Fe(OH)3 precipitation when adding ZnO to adjust pH value of 5. The solution was continuously cemented by Zn metal at 60 °C for 60 min to obtain Cu metal with high purity of 99 wt.% Cu. The purified solution with 37.64 g/l Zn was modified by Na2C03 to have pH value of about 6 and precipitation of ZnC03 (94.14 %).

PROSPECTS FOR THE APPLICATION OF COPPER MELTING SLAG IN ROAD CONSTRUCTION

The article discusses the option of strengthening the soils of the roadbed of highways with complex binders based on granular slag of copper smelting production and air lime. The characteristics of the investigated slag, photomicrographs of its surface, as well as the chemical and phase compositions are presented. A detailed description of the X-ray diffractogram of the studied slag with the processing of the obtained reflections using the ICDD PDF-2 database is presented. Calculations of hydrolytic equilibria were carried out using the main phases found from the data of X-ray phase analysis. It was found by the calculation method that at pH = 11-12 in the lime-slag mixture decomposition of iron silicates and aluminosilicates occurs with the formation of gels of iron and aluminum hydroxides, as well as amorphous silica. On the basis of the obtained complex binder, standard samples of strengthened soil based on loam were made and tested to determine the physical and mechanical properties. The results of the experiments carried out create an opportunity for obtaining hardened soils based on a complex mineral binder with a compressive strength of up to 2.2 MPa.

Indoor Air Quality in Steel Making Industries

Steel making industry is one of the major contributors to the global environmental catastrophes including climate change, photochemical smog and depletion of the ozone layer. Emissions from steel making process result in health impacts on workers and the neighboring communities. This study aimed to investigate indoor air quality in a steel making industry in Saudi Arabia. Indicative pollutants, SO2, NOx, CO, CO2, O3, PM10 and PM2.5 were measured at eight locations across the factory. The obtained results indicated that loading, melting, slag pouring and casting stages are the major sources of indoor air pollution. In comparison with the ambient air, indoor concentrations increased up to: 13.50, 9.8, 1.29, 2.7, 15.6, times for SO2, NOx, CO2, VOCs, O3, respectively. Periodical medical check, pollution control, using of uncontaminated scrap, compliance with H&S regulations, are the key factors in reducing indoor emissions and subsequently improve occupational health.

Extraction from aqueous solutions ions of iron and lead by filter loading, created on the basis of steel melting slag

The aim of the present paper is investigation of removal of Fe3+ and Pb2+ ions from aqueous media by material on the basis of steel melting slag. It has been established that the process of water purification from Fe3+ and Pb2+ ions by this material proceeds by a mixed mechanism both due to the formation of slightly soluble silicates and also due to the formation of hydroxides. When the filtration rate varies from 2 to 10 column volumes per hour, the percentage of sorption remains within 91,5–99,8%. The most optimal filtration rate is 6 column volumes per hour. Material on the basis of steel melting slag absorbs of Fe (III) up to 5 mg-eq/g and Pb (II) 0.64–1.27 mg-eq/g.

Chemical Aspects of the Obtaining of Iron-Containing Coagulant-Flocculant from Electric Steel Melting Slag for Wastewater Treatment

The possibility of producing iron and silicon-coagulant-flocculant for purification of waste water was shown. The electric steel melting slag JSC "OMK-Steel" has been used as the starting material, in which the content of iron oxide to 25.8% and silicon dioxide is 17.6%. The optimal parameters of slag hydrochloric opening were as follows: the modification time at T = 40 °C – 1 hour, the concentration of hydrochloric acid – 1.5 N, the ratio of the solid and liquid phases of S : L = 1 : 10. In these settings the concentration of hydrosilicic acid (for silicon) will be 1532 mg/l; the concentration of iron – 1250 mg/l has a lower concentration of silicic acid in the production of the solution with increasing temperature and time of exposure. This paper examined the chemical aspects of the process of obtaining the new iron-containing coagulant-flocculant based on electric furnace slag. The results can be used to produce coagulants and flocculants using industrial waste.

Use of the Electric Steel Melting Slag in Production of the Expanded Clay Gravel

The paper shows the possibility of production of the expanded clay aggregate with the use of electric steel melting slag up to 3.0 % produced by JSC “Oskol Electric Steel Works”. It was determined that at the temperature of 1170 °C the expanded clay aggregate with high strength properties and a high coefficient of swelling is formed. The preliminary thermal preparation of the samples with slag addition was at 500 oC. An opportunity to use iron-containing waste was revealed which lowers the temperature of the expanded clay aggregate burning. By means of the X-ray phase analysis the mineral mullite Al5SiO9.5 was found in the resulted samples of the expanded clay aggregate with an optimal addition of slag which reinforces a glass phase of granules and strengthens it. The results can be used for production of the expanded clay gravel with the use of industrial wastes. The technological scheme of the expanded clay production with the use of waste can be carried out without making any additional capital investments.

The Feature of Slag from Complex Hot Metal Blown by Converter Processing and its Influence on the Craft

The composition of the molten iron is complex because V-Ti ore is added in the blast furnace of Shuicheng Steel Corp. The physical and chemical property of the complex hot metal containing V and Ti, the steel slag from the complex hot metal were researched. The mechanism of foaming performance in slag and dephosphorization in melting slag process were clarified. And on this basis, the optimization of complex molten iron in converter process was carried and the effect was obvious.