Chromium free refractory material for RH vacuum furnace lining

Abstract

The chromium-free refractory material for RH vacuum furnace lining consists of one or several of magnetize, magnesia zirconia and magnesia zirconia silica 88-97 wt%, fine zirconia powder 1-6 wt%, fine zircon powder 0-9 wt%, and organic binding agent 1-3 wt%. It has the chemical composition of MgO 80-90 wt%, SiO2 1-4 wt%, and ZrO2 7-13 wt%. The organic binding agent is binding agent commonly for refractory material, such as sodium humate, calcium lignosulfonate, dextrin and Arabic gum. The MgO-SiO2-ZrO2 chromium-free refractory material has high slagging resistance and is significant for RH vacuum furnace to obtain long service life.

Description

technical field [0001] The invention relates to the field of refractory materials, in particular to refractory materials for furnace linings of RH vacuum smelting equipment. Background technique [0002] RH vacuum treatment is an important process and equipment in refining outside the furnace. It was jointly designed by Ruhrstahl and Heraeus in Germany, hence the name RH method. The refractory material used for the furnace lining of RH vacuum refining equipment needs to withstand the severe erosion of high-temperature molten steel, the melting erosion of slag and molten steel, and the intense thermal shock damage process of intermittent treatment of molten steel. The material is required to have excellent resistance to molten steel and slag. Erosion performance, good high temperature strength, and at the same time, the material is also required to have sufficient thermal shock stability. Magnesium-chromium products fired at ultra-high temperature, because of their excellent...

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Problems solved by technology

Hexavalent chromium is a carcinogen to the human body. It volatilizes during ultra-high temperature firing of refractory materials and high-temperature use under alkaline conditions. Waste refractory materials dissolve into groundwater during the process of stacking and landfilling. Waste refractory materials are discarded after separation of metamorphic layers during utilization. , crushing and dusting may cause the spread of such harmful substances and damage the environment

[0014] Some of the above chromium-free refractories cannot meet the requirements of replacing magnesia-chrome refractories for RH vacuum furnace lining due to slag resistance and service life, and some of them may be close to magnesia-chrome refractories in performance, but the production cost will be obvious This is the main reason why chromium-free refractories are difficult to replace magnesium-chromium refractories industrially on the lining of RH vacuum smelting furnaces

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