Waterproof lime dust used in coal mines is an important element in the system of protection against explosions. This is one of the oldest methods used to prevent coal dust explosions and, according to an expert’s opinion, it will remain so for a long time. T he work is a summary of research on the development of a new method of producing waterproof limestone dust to use it as an anti-explosive powder in coal mines. The typical method of hydrophobic dust production (milling limestone with stearic acid) is no longer profitable due to the restructuring of the mining industry. The main research was conducted on raw materials traditionally used during the production of anti-explosion powder, namely limestone meal with a grain size diameter equal to 80 μm (Czatkowice Limestone Quarry) and stearic acid as a modifier. Silicone preparation and bituminous preparation (Bitumenovoranstrich) were used as additional modifiers. The hydrophobization process was conducted with the use of different techniques: from stearic acid ether solution, from stearic acid vapor, from methyl silicone resin or bituminous preparation solutions. A series of research on modified powders to determine hydrophobization and flow properties was conducted. Depending on method of hydrophobization, the test of “floating on water”, the extraction of stearic acid was carried out, water contact angles on compacted material were determined, the thermal decomposition of powder was made. The increase in moisture after wet storage was indicated. The flow properties of powders were measured with the use of the Powder Characteristics Tester. The evaluation of the suitability of each hydrophobization methods in achieving the intended purpose was valued.

Contamination of the natural environment with petroleum pollution is still a frequent and particularly dangerous phenomenon, thus there is a need to remove these pollutants. Various types of mineral sorbents (silicate minerals, zeolites, perlite, diatomite, clay rocks) are highly valued in remediation processes due to their affordable, big selectivity and high efficiency. However, many sorbents are not resistant to moisture, which limits their use. The hydrophobization process improves the effectiveness of sorbents used in a humid environment. The DAMSORB produced by IM-POL was hydrophobized with a methanolic stearic acid solution. The use of cheap stearic acid as a modifier is economically advantageous. The evaluation of the hydrophobic properties of the modified material was performed on the basis of the results obtained from the tests: water absorption, floating on the water surface and the contact angles were determined. Tests of the sorption of petroleum-derived compounds were performed on the basis of three procedures: in accordance with the technical sheet of the leading producer of hydrophobic sorption materials in Poland, the Westighouse’s method in the oil layer and the Westighouse’s method on a flat surface. The modified sorbent floats on the surface of the water very well. The average value of the contact angle for the modified sample is 104 degrees. Material is super hydrophobic. In the water environment, the hydrophobized samples have a higher absorption capacity in relation to oil contaminations compared to the raw material. Features of the modified sorbent, such as good buoyancy on the water surface, low affinity to water and better absorption of oil from the solution, make it possible to use the material to remove petroleum contamination from water and highly moist surfaces.