Natural scales graphite is a high -quality refractory raw material, but it is difficult to prepare uniform and dense non -fixed refractory materials because the surface of graphite has hydrophobicity. Therefore, the surface of the graphite needs to be modified so that the surface is changed from hydrophobic to hydrophilic, in order to enable graphite to be widely used in refractory materials. Generally speaking, most of the surface modification uses the modified agent to modify the powder. The following introduces a variety of graphite modification methods.

First, the wetness of scales graphite and its application limitations. There is no shortage of graphite area, with small surface tension, and about 0.45%of volatile organic objects on the surface, all of which make the wetness of graphite worse. The strong hydrophobicity of the graphite surface makes the fluidity of the pouring materials worse, graphite is easy to reunite, it is difficult to prepare uniform and dense non -fixed -shaped refractory materials, and cannot be evenly scattered in the refractory material. The tissue and performance after high -temperature sintering depends to a large extent on the moisture of high temperature silicate liquid to graphite. When wetting, the silicate liquid phase flows into the particle gap under the action of capillary. The graphite particles are combined by adhesion to form a film around the graphite, and the continuous body is formed after cooling. Essence If it is not wet, graphite particles will form a gathering collective, and the silicate liquid phase will be limited to the gap between the particles to form isolated body, and it is difficult to sinter at high temperature to form a dense complex. Therefore, to prepare a carbon -resistant material with excellent performance, we must first improve the wetness of graphite. In recent years, people have made a lot of research on the surface modification of scales, made certain progress, and explored a variety of surface modification methods.

Second, the surface modification method of scales graphite: 1. Low -temperature 煅 burning graphite. The surface of graphite has 0.45%volatile organic matter, which is one of the reasons for the decline in wetting. After the graphite is burned 300 ~ 400 煅, its moisturizing properties have improved. 2. Surface activity agent modified graphite surfactant modification refers to the special structure of the surfactant, which sucks the hydrophobic group at one end of the surfactant to the surface of the graphite, and the hydrophilic group at the other end points to the water, thereby changing the graphite The surface nature is improved to improve its hydrophilicity. Surface active agent modified graphite is one of the early methods of the early days. It has the characteristics of low cost, simple craftsmanship, and obvious improvement of moisture. 3, crushing the green body method. Mix the graphite with other refractory materials in a certain proportion, suppress it into a raw blank on the press, bake it at a certain temperature, get a dense high -intensity raw blank, and then break the raw blanks into different particle size materials to introduce it into it into it. In the non -fixed refractory material, the purpose of introducing a large amount of graphite is achieved. 4, granulation method. Graphite or other refractory materials are used as the core of granular, that is, "granular core". Under the action of external forces, graphite or other refractory materials are bonded on the surface of the core through the bonding force of the adhesive. As the particle nucleus grows, it becomes large particles with a certain density and strength.