Influence of composition and cooling rate of alumocalcium slag on its crumblability

Abstract

The main components of metallurgical slags are iron compounds, which are extracted by reduction smelting. There are several types of this process with obtaining various products based on iron and slags of various compositions (aluminum-calcium self-disintegrating), etc. The mode of smelting and cooling of alumocalcium slag, formed during melting in the furnace, should ensure the most complete spontaneous crumbling of it, as well as high rates of extraction of REM from it. Synthetic slags similar in phase composition to industrial samples after smelting of iron-containing ores were selected for the experiments. The simulated samples correspond to the region of primary crystallization of bicalcium silicate on the triple state diagram of CaO – SiO2 – Al2O3 system. The slag after crumbling was subjected to a sieve analysis using a mechanical sieve. In the experiments, slags with a silicon module k = 2.0 were used, which actively crumbled during their cooling. With an increase in the silicon module, the crumbling deteriorates. It was established that it is impossible to precisely limit the areas of compositions of crumbling slags at certain cooling rates. The conducted studies showed that the crumblability of slags improves as it approaches the center of the bicalcium silicate region. The composition of slags close to composition of the intersection points of the lines 2CaO·SiO2 – 2CaO·Al2O3 and 2CaO·SiO2 – 12CaO·7Al2O3 with the lines of the permanent silicon module granulometric composition almost does not depend on the cooling rate. The temperature mode from smelting to cooling affects the slags crumblability. The most promising are slags with a silicon module in the range of 2.85 – 3.00, close to the phase triangle 12CaO·7Al2O3 – 2CaO·SiO2 – 2CaO·Al2O3 .

The Physicochemical Basis for the Production of Rapeseed Oil Fatty Acid Esters in a Plug Flow Reactor

“…Regarding the apparatus design process, the simplest and most common method used in the industry is the batch reactor of ideal mixing, which is a vessel with a heating element [62,63] and a stirring device [54,64]. Continuous reactors are also widely used in industry-flow-through apparatuses that enable a constant supply of reagents and product withdrawal [64][65][66].…”

Method for Decontamination of Toxic Aluminochrome Catalyst Sludge by Reduction of Hexavalent Chromium

“…From this, we can conclude that all industrial waste containing hexavalent chromium must be thoroughly recycled. Alumochrome catalyst sludge is not recycled and is stored in special landfills, which leads to the accumulation of large-scale hazardous waste [12][13][14]. The storage of highly toxic sludge is costly and creates environmental problems, such as the pollution of sewage, groundwater, and air space, and has a detrimental effect on the health of living organisms [15][16][17].…”