RESOURCE-SAVING PROCESS OF CERAMIC MATERIALS PRODUCTION

Man’s intensive economic activities lead to exhaustion of natural raw material resources. At the same time the volume of industrial wastes is growing.

The proposed small energy consuming process would make it possible to solve these problems at the expense of reprocessing of metal-containing industrial wastes into special ceramic materials (heat-proof, pigment, filtering, etc.) by way of the thermosynthesis in a mode of controlled burning with external heating.

Wastes reprocessing starts from the analysis of their composition. Knowing the chemical composition of metal-containing slime and on having proportioned the special additives, one could provide the optimal mode of exothermic reaction running with subsequent transfer of all the toxic compounds of heavy metals into the stable insoluble formations of the type of spinel, cordierite, garnet, etc.

The oxides of heavy metals are kept in such structures so strongly that the resulting ceramic materials possess a very high chemical and thermal strength and become non-toxic.

Two independent ecological expertise by environmental agencies have confirmed the ecological safety of the process. It has been recommended as a basic process for the c reaction of self - sufficient regional centres for toxic metal-containing wastes reprocessing in order to sanitate the ecological situation.

The general diagram of metal-containing wastes reprocessing includes the following phases:

components blending compacting thermal disintegration

preparation synthesis

For particular kinds of products some phases are missing. For example, no disintegration is needed to obtain heat-proof and filtering ceramic materials. The main phase - thermal synthesis - may be conducted in two different modes.

The first is the mode of controllable burning, making it possible to reduce the energy consumption when carrying out the synthesis, but it requires the observation of stringent requirements on the content of the oxidisers, reducing agents and industrial wastes in the initial stock.

The second mode is based on the fact that the wastes containing iron and other metals with high reaction capabilities may be reprocessed in a more mild mode with the external heating. Hereby the share of wastes in the blend may reach 85%. The usage of the heat of exothermic reactions makes it possible to reduce the necessary temperature of ceramic materials synthesis from 1200-2000 ⁰C of the traditional process to 500-800 ⁰C and to use ordinary industrial furnaces for the production.

The cost of obtained materials is 1.5 - 2 times lower in comparison with the known processes, the most cost-efficient being the reprocessing of metal-containing wastes into thermal-resistant non-organic pigments.

The proposed process may serve as a breakthrough to the technologies of the XXI century, providing the complex saving of resources (chemical raw material, energy), reduction of products cost and solution of ecological problems at the expense of the reprocessing of metal-containing wastes.

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