On the heat units in the refractories industry where imperfect dust removal occurs (Davidson cyclones, one- and two-stage cyclone structures) giving a level of gas purification of not more than 90%, it is necessary to install additional stages of purification or to replace the existing dust extractors by those which are more effective. For the drying of clays in drying drums to a final moisture content of not more than 14%, the most effective dust extractor is the electrofilter. It is also possible to use two-stage extractors made up of NIIOGAZ cyclones in the first stage and wet dust extractors (rotary network filters, etc,) in the case of using the slurry method and when heating the drum with nonsulfur fuel. With the drying of clays to a final moisture content of about 18%, it is adequate to use a single-stage dust cyclone made of NIIOGAZ cyclones. When drying chromite ores and magnesite in a drying drum, it is desirable to install two-stage dust extractors made up of NIIOGAZ cyclones in the first stage, and battery cyclones or wet-dust extractors in the second, until we have better data. For rotary furnaces used for firing clays into grog, it is adequate to installone-stage dust extractors-electrofilter, and behind the furnaces used to fire dolomite and magnesite, to instal a two-stage unit made up of NIIOGAZ cyclones in the first stage and electrofilters in the second. It is essential to make a detailed study of the operations of existing dust extractors to clarify measures aimed at getting a high degree of gas purification. To reduce the dust removal level from furnaces, it is desirable in the future for the firing of refractory materials, especially dolomite and magnesite, to use rotary furnaces with preparatory conveyer grids, and also shaft preheaters in the rotary furnaces used at the present for firing clay into grog. One-stage dust extractors made up of battery cyclones in furnaces used for firing dolomite and magnesite should have a second stage also made up of battery cyclones, but with a lower element diameter.