Compact forsterite fire-resistant raw material and preparation method thereof

Abstract

The invention relates to a compact forsterite fire-resistant raw material and a preparation method of the compact forsterite fire-resistant raw material. The technical scheme of the invention is as follows: the preparation method comprises the following steps of: mixing 69wt%-85wt% of talcum powder, 13wt%-30wt% of fine powder of magnesian raw material, and 0.2wt%-2wt% of an additive to prepare a mixed material; then adding 1wt%-10wt% of a bonding agent relative to the mixed material, and ball-milling the mixed material and the bonding agent in a ball mill for 1-3 hours to prepare a ball-milled material; then adding 3wt%-10wt% of water relative to the ball-milled material in the ball-milled material, stirring for 10-30min, forming a blank body by pressing and drying; and finally calcining the dried blank body at 1350-1650 DEG C, keeping the temperature for 1-3 hours, and then obtaining the compact forsterite fire-resistant raw material. The compact forsterite fire-resistant raw material disclosed by the invention has the characteristics of being low-cost in production and easy to sinter, and the prepared compact forsterite fire-resistant raw material has large volume density, low porosity and stable high temperature property.

Description

technical field [0001] The invention belongs to the technical field of refractory materials. In particular, it relates to a dense forsterite refractory raw material and a preparation method thereof. Background technique [0002] Forsterite crystal has a melting point of 1890°C and is an island silicate structure. It has excellent characteristics of high melting point, low thermal conductivity, stable chemical properties, and high corrosion resistance to metal melts and slag. However, natural forsterite not only has high impurity content but also has a large loss on ignition, even after high-temperature calcination, it still cannot meet the requirements of high-grade refractory products. Fe contained in natural forsterite 2 o 3 , SiO 2 and Al 2 o 3 Such impurities will form low-melting materials in minerals or at high temperatures, such as fayalite, forsterite, diopside, anorthite, cordierite, etc., which will reduce the refractoriness and load softening temperature of ...

AI Technical Summary

Problems solved by technology

However, natural forsterite not only has high impurity content but also has a large loss on ignition, even after high-temperature calcination, it still cannot meet the requirements of high-grade refractory products.

Natural forsterite contains such as Fe2O3, SiO2 and Al2O 3 and other impurities will form low-melting materials in minerals or at high temperatures, such as fayalite, forsterite, diopside, anorthite, cordierite, etc., which will reduce the refractoriness and Load softening temperature; due to the existence of impurities, various mineral phases coexist, resulting in unstable properties of refractory products at high temperatures, which seriously affects the production of refractory materials and the promotion of refractory products

[0003] There are also some methods for preparing forsterite in the prior art, but there are certain deficiencies: such as using serpentine tailings as the main raw material (Wan Jiandong, Research on the conversion of serpentine tailings into forsterite in Donghai County. Nonmetallic Minerals, 1997, 3: 61-63) preparation technology, through fine grinding, molding and firing to obtain dense forsterite raw materials, but due to the The high content of impurities such as Fe2O3 and CaO makes the high-temperature properties of the prepared forsterite unstable, which limits its application in refractory products; The patented technology of "Method for Synthesizing High-purity Forsterite with Magnesite Tailings and Talc Tailings" (201110159148) uses magnesite tailings and talc tailings as the main raw materials, adds additives and binders, and proceeds through batching and mixing , forming, drying, high-temperature synthesis and crushing processes to produce high-purity forsterite refractory raw materials with a temperature higher than 1600°C and a bulk density greater than 2.55g / cm3, but the raw materials used in this technology and The product contains a certain amount of iron oxide, which will affect the use effect of the final product at high temperature. Due to the limitation of the preparation method, this technology cannot produce high-density forsterite. For example, under the premise of ensuring excellent high-temperature performance, the bulk density Densified forsterite greater than 2.9 g / cm3; another example is the patented technology of "Method for producing forsterite refractory material from iron tailings" (ZL200610047981), which combines iron tailings with lightly burned magnesium Add olivine clinker, combustible matter, binder and water to the mixture of powder, stir, form, dry, keep warm and burn to make forsterite refractory material. The raw materials used in this technology have higher The content of iron will significantly affect the high-temperature performance of the product, and then it cannot be used for a long time in a high-temperature environment in contact with corrosive media, reducing atmosphere, alkaline dust, etc.; another example is "light forsterite brick and its manufacturing method" ( 200610134805) patented technology, mixing olivine sand, magnesia, coke and charcoal, etc., drying, firing, cutting and grinding to produce light-weight forsterite bricks with a service temperature of 1540 °C

[0004] In short, there are some deficiencies in the preparation methods of forsterite materials or forsterite bricks in the prior art: or the raw materials contain impurities such as iron and calcium, Lead to instability of the high temperature properties of the product; or the prepared product is a lightweight material

Therefore, they cannot meet the requirements of bulk density, porosity, and high temperature properties of refractory products in high temperature environments that are in contact with erosive media, reducing atmospheres, and alkaline dust.