Preparation of SiC from acid‐leached coal gangue by carbothermal reduction

Abstract

For the comprehensive utilization of coal gangue, acid‐leached coal gangue was used as silicon source and part of carbon source, low ash anthracite and degreasing cotton were added respectively as supplementary carbon source, SiC and SiC fiber were prepared by carbothermal reduction method accordingly. The results show that the main components in leached coal gangue are amorphous SiO2 and carbon, which are suitable for the synthesis of SiC as raw materials. The synthesis temperature and holding time have important influence on the synthesis of SiC, and the optimum synthesis parameters for SiC are at 1550°C for 4 hours; under this condition, the yield of SiC is 78.27%, and the specific surface area is 6750 cm2/g. The results show that the resulting products are essentially composed of β‐SiC with a minor amount of α‐SiC. Besides, based on the carbon fiber transformation method, SiC fiber was prepared by using leached coal gangue and degreasing cotton as raw materials. Therefore, it can be concluded that leached coal gangue is a very effective and inexpensive source for preparing SiC, and more importantly, this work has important economic and social significance to realize waste recycling and control pollution.

SiC‐based porous ceramic carriers for heat‐conductive phase change materials through carbothermal reduction method

“…iron tailings, porous materials, reaction sintering, reduction, silicon carbide, thermal conductivity particles, rendering them to be suitable for sintering. [14][15][16] It is shown that combining the carbothermal reduction with the nitridation process can also produce high thermal conductivity AlN ceramics. 17 and high porosity porous silicon nitride ceramics for filters and catalyst carriers.…”

“…The carbothermal reduction is an attractive method to prepare carbide ceramics with high performance due to the extensive raw material sources, low process cost and simple operation. The products possess high purity and small‐sized particles, rendering them to be suitable for sintering 14‐16 . It is shown that combining the carbothermal reduction with the nitridation process can also produce high thermal conductivity AlN ceramics 17 .…”

Magnetite and Carbon Extraction from Coal Fly Ash Using Magnetic Separation and Flotation Methods

“…The Omsk CFA mainly contains 20-35 wt % alumina, 50-65 wt % silica, 5-15 wt % magnetite, and up to 6 wt % unburned carbon [1,2]. Previous research was aimed mainly at studying methods for producing alumina [3][4][5][6], ceramics [7][8][9][10], coagulants [11,12], and the extraction of the rare-earth elements [13][14][15][16][17]. Our previous research was about the leaching of alumosilicates with hydrochloric acid…”

Influence of surface oxide layer of SiC powder on the rheological properties of its slurry

“…[1][2][3] However, a uniform ceramic slurry having a high solid content and a low viscosity must be prepared that is a prerequisite for the implementation of this process. [1][2][3] However, a uniform ceramic slurry having a high solid content and a low viscosity must be prepared that is a prerequisite for the implementation of this process.…”

“…The colloidal process is one of the effective methods to prepare high reliability, high density, and complex silicon carbide (SiC) ceramic components. [1][2][3] However, a uniform ceramic slurry having a high solid content and a low viscosity must be prepared that is a prerequisite for the implementation of this process. 4,5 It is well known that high solid content and low viscosity are contradictory.…”