Cold rammed paste is a relatively temperature sensitive item, and for us, its temperature is also very important. Among the items that care about temperature, what kind of temperature is suitable for cold rammed paste? What our editor is discussing today is the knowledge points in this area, so that we can have better development in cold ramming.

A cathode paste that can be used for masonry construction at room temperature. The aggregate of this cathode paste is the same as that of ordinary cathode paste (also known as hot rammed paste), such as ordinary calcined anthracite or electric calcined anthracite, metallurgical coke, graphite chips, etc. The low softening point of the adhesive is 20 ℃± 5 ℃. Cold rammed paste has a low softening point and high volatile content. It should be packaged in double-layer woven or plastic bags, with a shelf life of 6-9 months. The construction temperature of cold rammed paste is 25-50 ℃. In summer, it can be constructed at ambient temperature. In spring and autumn, the effect of low ambient temperature can be compensated for by soaking the paste. The stewing temperature is 40-50 ℃. Building furnaces in northern winter can affect the quality of masonry and the lifespan of grooves.

Before the 1970s, the hot ramming paste or aluminum electrolysis cell used in China's aluminum industry borrowed coarse seam paste, fine seam paste, or paste using petroleum coke as aggregate from ironmaking blast furnaces. The use of medium temperature coal tar asphalt as a binder results in high construction temperature, poor environmental conditions, high labor intensity, and difficulty in ensuring construction quality. In the 1970s, carbon materials called cold rolled paste with a softening temperature below 80 ℃ were developed for use in ironmaking blast furnaces and aluminum electrolysis tanks.

With the enlargement of aluminum electrolysis cells and the updating of cathode carbon blocks, people have begun to pay attention to the matching use of cathode paste and cathode carbon blocks. The main raw material for producing cold rammed paste has eliminated petroleum coke and commonly uses ordinary calcined anthracite and high-temperature electric calcined anthracite, with a small amount of graphite added. Cold rammed paste has become a specialized material for aluminum electrolysis cells, widely used nationwide and promoted to large cells. The following table shows the quality status of cold rammed paste. In order to match with the titanium borate composite cathode block, a titanium borate composite cold ramming paste was developed. The commonly used formula for cold ramming paste is as follows: (1) binder. 15% to 16% of the total paste. Softening point 20 ℃± 5 ℃. Its composition is: ① Medium temperature coal tar pitch 70% ± 2% anthracene oil 30% ± 2%; ② Medium temperature coal tar pitch 40% ± 2%+coal tar 50% ± 2%.