OLEOPHILIC SORBENTS BASED ON GRANULAR FOAMED SILICATE: PROPERTIES AND FEATURES OF REGENERATION

The solution to the problems of ecological safety when cleaning water objects from organic pollutants is indissolubly related to developing new sorbents and improving the technologies of their synthesis. Various materials in dispersed and granulated forms are successfully used in the production of sorbents. This article deals with the development and improvement of the technologies for producing the sorbents of petroleum and petroleum products. As a basis for the development of new sorbents, the properties of the granular foamed silicate obtained from the siftings of waste products from mining and processing plants were studied. The trial batches of oleophilic sorbents were obtained through thermochemical modification of hydrocarbons in the gas-vapour phase. It has been established that foamed silicate does not change its porous structure and amorphous state after thermo-chemical modification, retaining the high sorption activity. The nature of the porous structure of sorbents and the influence of porosity on their key properties, such as oil capacity, water absorption, and buoyancy, are investigated. The studies of the fractions of modified foamed silicate revealed low water-absorption capacity of the coarse- and middle-sized fractions. The minimum water absorption was determined for the fine fraction of the modified material, which is related to the absence of pores in these samples. Determination of oil capacity characteristics provides evidence of high oil receptivity and sorption capacity of the modified foamed silicate with respect to petroleum products. The results of experiments on sorbent regeneration after the end of its service life are presented. The developed semi-production experimental plant for the modification and regeneration of porous loose materials in the fixed bed is presented. The technological scheme of regeneration is proposed, allowing for regeneration and repeated modification of the used sorbent during one processing stage without any decrease in its sorption properties. The advantage of the developed technology of sorbent properties recovery is in the implementation simplicity and economic rationality. The repeatedly modified sorbent retains its characteristics and, first of all, sorption properties with respect to petroleum products. The practicability of developing new sorbents of petroleum products based on granular foamed silicate is demonstrated.