The resulting ternary slag contained in mass percent about 3040% mgo, 3040% al2o3 and 2030% sio2. Previous researches have shown that the content of alumina in such slag can be as high as 29%. Economic and environmentally beneficial treatment of slags. Ferrochrome slag ph was measured as per the method outlined in astm method 9045d 6 to 20 g of waste sample in a 50ml beaker, 20 ml of reagent water was added. The ferrochrome slag aggregate properties are determined and tabulated in table 4. Present status of refractories for ferroalloy industry. The slag consists mainly of sio 2, al 2 o 3, and mgo in different phases such as spinel mgoal 2 o 3 and forsterite mgosio 2 as well as chromium and iron oxides and fewer amounts of other metal oxides. The chromium from liquid extract is separated with fly ash based zeolite which has 3000 mmolgram and it can be regenerated to recover chromium. Chemical composition of ferrochromium slag can be altered suitably for application in high. Property natural coarse aggregate ferrochrome slag aggregate fine aggregates. Zimbabwes major producers of ferrochrome cut back on production approx.
In case of substitution of ferrochrome silicon used as a reductant in lowcarbon ferrochrome production for less expensive ferrosilicoaluminum, made of industrial wastes, it is possible to have a slag with a nearhelenite phase composition. Further, it is also used as main source for niobium alloying of hsla. Slag and furnace dusts flue dust are generated as waste in enormous quanti ties during ferrochrome production. Ageing characteristics of ferrochrome slag report no 0642011 rev 4. Ferrochrome, or ferrochromium fecr is a type of ferroalloy, that is, an alloy between chromium and iron, generally containing 50% to 70% chromium by weight ferrochrome is produced by electric arc carbothermic reduction of chromite. Ferrochrome article about ferrochrome by the free dictionary. The typical ferrochrome slag composition is 30 % sio 2, 26 % al 2o3, 23 % mgo and 2 % cao. Duplex process for production of low carbon ferrochrome. Important factors are temperature and composition of the slag, viscosity and electrical conductivity. The main component of chromium slag is chromic oxide, silicon oxide, magnesium oxide, alumina, calcium oxide and iron oxide. Ferro chrome slag crushed aggregates uk page 1 of 3. Directory of ferro chrome manufacturers,ferro chrome exporters,ferro chrome wholesalers,ferro chrome suppliers, traders for your business needs zinc. Pdf research on the use of ferrochrome slag in civil.
With the exception of potassium k, which had a potential leaching capacity availability test of around 16%, the leaching of chromium, nickel, zinc and other elements was just a few. It is now well recognised that the physical, chemical and thermal properties of aggregates substantially influence. Slags also arise from other processes, particularly the smelting of nonferrous metals, but these materials can be very different and each needs to be studied individually. Slag is usually a byproduct of metal production, although there are processes such as ilmenite smelting, for example where the slag is the principal product. Slag from the production of ferrochrome is also included here. Ferrochromeferrochrome manufacturers, suppliers and ferrochrome slag is a byproduct from the production of sell offer spot fecr 60% safricaindia hc ferrochrome of nitrogen b. Environmental impact of ferrochrome slag in road construction.
Cao 10 mol%, sio2 40 mol%, mgo 35 mol% and al2o3 15 mol%. In ferrochrome smelting operations, the manganese should find its way into the slag rather than the metal. Aim of this work was to prepare conventional castable and low cement castables by utilizing this waste ferrochrome slag, calcined bauxite and microsilica. Ferrochrome production, chromite ore stainless steel. Journal of chemical and pharmaceutical research, 20, 55.
The replacement of ferrochrome slag with conventional coarse aggregate in concrete for m25 grade and even high strength m50 grade concrete for every incremental of 25%replacement up to 100% can. Manganese in mineral chromite, ferrochrome slags, and ferrochrome acid digestion of ferrochrome metal analysts assigned to make a new determination on a sample often must deduce the significance of steps in the usually sketchy procedure descriptions of. Typical composition of ferro chrome slag is shown below in table 1. Ferrochrome is not known to contain any 0,1 % or any 2 o 3 and magnesium oxide mgo, as well as a small amount of sulfur s, while steelmaking slag contains iron oxide feo and magnesium oxide mgo. The latter slag type is presented in figure 5 and figure 6. The slag also includes cr and fe oxides and calcium oxide. The ferrochrome slag aggregate is confirming to is.
It is now well recognised that the physical, chemical and thermal properties of aggregates substantially influence the properties and performance of concrete. Ferrochromium market poised to register healthy expansion. South africa, the leading producer of ferrochrome does not take ad. The typical ferrochrome slag composition is 30 % sio2, 26 % al2o3, 23 % mgo and 2 % cao. Looking to source suppliers of ferro chrome slag crushed aggregates in uk. Assessment of ferrochrome slag for lanfill disposal report no 0802011 rev 1. Another raw material is natural zeolite obtained from rota madencilik. The outcome from this was the development of a roadmap, which proposes how the utilization of ferrochrome slag might be increased. Recovery of chromium from ferrochrome slag article pdf available in international journal of research in pharmacy and chemistry 2055. Ferrochrome smelting slag slow cooled from the furnace showing the precipitation of. Ferrochromium is consumed extensively in the manufacturing of steel to achieve the qualities such as corrosion resistance, tensile strength, heat resistance and yield strength.
Ferrochromium, also known as ferrochrome, is an alloy of iron and chromium containing 50 to 70% of chromium. The pycnometer used is a manual micrometrics multivolume 5. Fluxing to produce the required slag composition was carried out using either silica or a combination of silica and lime in the form of burnt lime or limestone. Surging demand for ferrochrome used in making ferroalloy, which in turn is used in making stainless steel, has led to a severe shortage of chromite. The complete book on ferroalloys ferro manganese, ferro. The chrome content in the slag is about 8 % and the iron content 4 % respectively. Steel slag utilization in asphalt mixes mf 1861 page 4 steel slag from furnace linings, but the major problem results from using ladles and pits as waste receptacles in the furnace areas. The results obtained in the present study are compared with synthetic as well as slag samples as per the specifications of manufacturers. May 18 may guizhou highcarbon fecr production capacity release in 2020.
Some slags are basically unstable at high temperatures since two or more components in the slag will react and the composition will change continuously eg esr slags where fluorides and oxides react eg. Basics of slag production article on the slag industry. It can be seen that the solubility of crox in the slag is about 60 mol%, if the slag is. Ninita enterprises, rasulgarh, bhubaneswar in odisha.
To obtain mortars consisting of waste materials was also an. Slag samples from a ferrochrome smelter were analyzed using an xrf powder pellet analytical technique in contrast to the rep technique used at the plant laboratory, to determine their composition. The chromium from liquid extract is separated with fly ash based zeolite which has 3000 mmolgram. May 20 analysis of china hc ferrochrome production costs in sichuan in may 2020. Effects of activator properties and ferrochrome slag. The main objective of this study was to investigate the effects of activator type and curing conditions on the compressive strength and electrical resistivity of alkaliactivated ground granulated blast furnace slag mortars.
The conventional process for high carbon ferro chrome he fecr in sub merged arc. Research on the use of ferrochrome slag in civil engineering. Ferrochrome slag ore beneficiation process introduction and flowchart. The composition and leaching tests of the ferrochrome slag show that the chromium content is high, %, although leaching under normal conditions is very low. Implementation of industrial waste ferrochrome slag in. The slag composition is tested every day by sampling and analysis. Fecr slag mineralogy to study chromium bearing mineral phases and other mineral phases. The material properties of these slags show excellent properties for reuse in the construction industry. Common phases in the slag are glass, spinels al 2 o 3 mgo and forsterite mgosio 2, and small amount of cao. Ferrochromium also ferrochrome, a ferroalloy containing approximately 70 percent cr fe and impurities constituting the remainder. Development of high strength concrete using ferrochrome. Microscopic studies to evaluate the chemical composition and structural aspects of different phases present in slag matrix.
Ferrochrome aluminothermal slags as a multifunctional. The samples were covered, and continuously stirred and were kept in suspension for 5 min. The chemical composition of the slag used is presented in table 1. Even though the slag has the desired engineering and mechanical properties, its use has been restricted because of leaching of chromium often exceeding the regulatory norms under adverse environmental conditions.
Fortunately, the value of steel slags is increasingly being recognized, particularly for return to blast furnace burden, and contamination is avoided. Batch composition of ferrochrome slag based castables. May 19 may guangxi highcarbon fecr production capacity release in 2020. Experience is reflected for application and prospective areas are considered for utilization of ferrochrome slag. Recovery of chromium from ferrochrome slag is 64% by treatment of slag with lime at 973k in solid phase. Environmental and technical assessment of ferrochrome slag. Such supply condition is driving up prices of chrome ore.
Criteria document for the classification of ferrochrome slag in accordance with sans 10234. The results of the activities of the chromium oxides are presented in figure 3. Most of the chromium left in high carbon ferrochrome slag was found to exist as undissolved. Chromium ores 5258 percent cr2o3 serve as the raw material in the production of ferrochromium. Ferrochrome production for metallurgical applications uses up more than 90% of the worlds chromite output of about 19 m tonnesy. Using modern process control and good quality charge materials the optimal slag composition can be attained.
It is produced by electric arc melting of chromium ore and chromite. The smelting point of the slag has to be higher than the metal smelting point, because metal is heated up by using slag liquid phase. Ferrochrome slag, a major solid waste in ferrochrome industries faces the disposal problem because of residual chromium content in it. Ferrochrome slag ore beneficiation process introduction. Data from these analyses have most often been used to trace the partitioning of the manganese through the smelting process and for material balance calculations. Production, characteristics and use of ferrochromium slags 173 2. Typical composition of slag in the ladles is as follows. The main components of the slag are sio2, mgo and al2o3. Implementation of industrial waste ferrochrome slag in conventional. Pdf utilization of ferrochrome wastes such as ferrochrome ash. The complete book on ferroalloys ferro manganese, ferro molybdenum, ferro niobium, ferro boron, ferro titanium, ferro tungsten, ferro silicon, ferro nickel, ferro chrome an alloy is a mixture or solid solution composed of metals. Information is summarized and results are provided for comprehensive study of ferrochrome aluminothermal slags carried out over several decades by both home specialists and the authors of the article.
Chromium slag is waste residue containing chromium when pyrometallurgical smelting ferrochromium alloy, at present mainly produce by using submerged arc furnace to produce high carbon ferrochrome. Ca 0 50 to 55 % mg0 8 % si02 26 % the basicity of slag is about 2. Ferrochrome is an inorganic material and it is not classifiable as a pbtvpvb substance. In the case of steelmaking slag, the slag contains metal elements such as iron in oxide form.
Manganese in mineral chromite, ferrochrome slags, and. Production, characteristics, and use of ferrochromium. Slag properties and their role in smelting operations. Recovery of chromium from ferrochrome slag open access. A process for the recovery of chromium and iron oxide. Ferrochrome slag is a byproduct from the production of. Low carbon ferro chrome offered comprise ferrochrome ortant chromium ore. May 19 high carbon ferrochrome producers are bullish on the outlook. This was done to evaluate the possibility ofusing xrf as an alternative technique to improve the turnaround times at the plant laboratory. Neutron radiation tests about fecr slag and natural. An innovative way of utilizing ground granulated blast furnace slag is to activate it using alkaline materials. Similarly, ferroalloys are the mixture of iron with.
1165 1424 428 791 1147 1218 815 541 1563 756 832 764 1204 1030 609 1551 1467 408 1261 794 973 949 775 371 1567 1370 827 900 653 559 471 203 808 1483 1400 165 1269 299 834 1058 1166