In the past two decades, the technology of the agglomeration of dispersed materials and fines by briquetting method is becoming widespread in metallurgy. From all known briquetting technologies (roller presses, vibro-press and etc.) the technology of stiff vacuum extrusion, developed by J. C. Steele & Sons, Inc. (United States) and successfully adapted by A.M. Bizhanov with colleagues for the needs of the metallurgical industry, is considered as the most promising at present time and for the nearest future. With a view to clearly denote the technological features of this method of briquetting A.M. Bizhanov put into use a new term-BREX (extrusion briquette) that is already being widely used in practice and in the publications.
The main features of stiff extrusion, defining its attractiveness for metallurgy and mining, and its fundamental difference from competing technologies are:
1. High mechanical strength of "green" BREX, due to the application of the vacuum in the working chamber of the extruder that allows removing more than 93% of the air from the mix. This leads to an increase in the density of the mixture prior to agglomeration, ensures high strength with less expense of the binders than with other briquetting technologies and does not require heat treatment to achieve a working strength of BREX and makes easier the logistics of the handling operations.
2. The possibility of production of BREX of the optimal size and shape in terms of metallurgical technology in which they are used, which is achieved by simply changing the profiles and dimensions of die holes;
3. High strength properties of cured BREX which allows loading, unloading and transportation with minimal fines generation, and high hot strength of the BREX;
4. Possibility to efficiently agglomerate wet mixes (up to 18-20% of the moisture contents), resulting in lower costs to the draining of the charge;
5. Low energy cost of pressing in the working chamber at pressures up to 3.5 Mpa;
6. Industrial excellence of the technology, a century of experience in manufacturing and maintenance, high reliability, durability and economic efficiency of the equipment produced by J. C. Steele & Sons, Inc.