Additive for producing macrocrystalline fused magnesite

Abstract

The invention relates to an additive for producing macrocrystalline fused magnesite. Main components of the additive are high purity graphite powder, rare earth oxide composition and zirconium oxide. The additive is characterized in that the addition mass of the high purity graphite powder accounts for 0.5-5% of the mass of magnesium oxide, the addition mass of the rare earth oxide accounts for 0.01-1.5% of the mass of magnesium oxide, and the addition mass of zirconium oxide accounts for 0.1-3% of the mass of magnesium oxide. The massive white transparent high purity fused magnesite is obtained by pointedly adding corresponding impurity removal materials according to the type and content of impurities in the magnesium oxide raw material in combination with an appropriate technological process; the technological process is simple; the dosage of the additive is small, but the additive has an obvious effect. Due to optimization of the additive and the technology, the melting power and time are reduced, the utilization rate of raw materials is increased, and the effects of energy conservation and emission reduction are achieved. The additive is easy to obtain, simple in process, low in cost and suitable for large-scale industrial production and application; requirements for required equipment are low.

Description

【Technical field】 [0001] The invention relates to the technical field of refractory production, in particular to an additive for producing large crystal fused magnesia. 【Background technique】 [0002] Most of the existing high-purity fused magnesia smelting directly uses natural magnesite ore or light-burned magnesia to smelt directly in a three-phase electric arc furnace. The smelting time is long, the utilization rate of raw materials is low, and the environmental pollution is serious. The purity of fused magnesia produced is mostly lower than 98%, and the content of impurities is high, especially SiO 2 , Fe 2 o 3 , CaO, A1 2 o 3 The content is high, and the color of the product is mostly not pure white and transparent, and yellow, brown and green appear to varying degrees, which cannot meet the use requirements of specific fields. Down figure 1 It is a schematic diagram of the melting and crystallization process of fused magnesia. [0003] According to the industry...

AI Technical Summary

Problems solved by technology

However, these additive combinations do not strictly control the introduction of foreign elements, and some additives only focus on lowering the melting point of the system, and do not specifically remove impurities, but instead cause the content of elements such as sodium, calcium, and silicon to increase and enrich. It makes the Ca / Si ratio decrease, which does not meet the requirement of greater than 2 for general industrial applications

Moreover, the rare earth ytterbium tantalum cerium samarium magnesium alloy needs to be prepared with rare earth oxides, the process is complicated, the impurity content of the alloy is not strictly controlled and the cost is high

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