This paper presents the results of research on the granulation process of leather industry waste, i.e., tanning shavings. It is economically justified to granulate this waste together with mineral additives that are useful in the processes of their further processing. Unfortunately, the granulation of raw, unsorted shavings does not obtain desired results due to their unusual properties. In this study, the possibilities of agglomeration of this waste were examined by a new method consisting of the production and then the granulation of wet pulp. During granulation, no additional binding liquid is added to the granulated bed. As part of this work, the specific surface of granulated shavings, the granulometric composition of the obtained agglomerates, and their strength parameters were determined. The use of a vibrating disc granulator, the addition of a water glass solution (in the pulp), dolomite, and gypsum made it possible to obtain durable, mechanically stable granules.

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The work presents a comparison of methods of granulating waste – tannery shavings – from the leather industry. This waste is often used for the production of leather composites, but it creates a number of problems in transport and storage. It seems that granulation of this waste together with mineral additives needed in their further processing is a solution. However, the traditional method of granulation involving the gradual moistening of a loose deposit on a moving surface of the granulator does not give the desired results for the granulation of material with such unusual physical properties. Therefore, new methods have been proposed to eliminate the disadvantages and limitations of traditional granulation. The methods proposed differ in the way the binder liquid and mineral material are applied. They consist in soaking the shavings with binding liquid beforehand, removing excess liquid, and then granulating the wet pulp with the addition of selected fine-grained mineral material. Analysis of the results was based on a comparison of the granulometric compositions and compressive strength of the agglomerates obtained.

This paper analyses the possibility of using tannery shavings as a basis for new composite materials with specified properties. The new material was made by combining tannery shavings with an adhesive medium. Mineral additives, such as dolomite, kaolin and bentonite were used in an amount of 5% and 10% of the total mass of shavings as a filler. In order to point out the influence of mineral additives on the final composite structure, some physico–mechanical properties, such as tensile strength and elasticity were examined with the use of static tensile tests. The second part of the investigation involved the analysis of wetteability by immersion, because this property depends on several aspects, such as surface roughness and the material structure. Thus, changes in wetteability values can provide information about the impact of mineral additives on the material properties of composites. With regard to physico–mechanical and sorption properties obtained on the basis of experimental results, it was possible to define areas of possible applications of these materials in comparison with current methods.

This work concerns non-pressure granulation of mineral materials used for the production of agricultural fertilizers for soil deacidification. In order to expand the product range of Nordkalk Poland sp. z o. o. located in Poland, the granulation conditions of the gypsum–lime mix were examined with the use of various granulation methods. The processed mixture was Jurassic lime flour mined in the Sławno mine (Poland) and waste gypsum (sulfogypsum) obtained from the largest coal-fired power plant in the EU, Bełchatów Power Plant (Poland). This paper presents the results of the optimization of the gypsum–lime fertilizer granulation process. The results of the study of granulation of gypsum–lime mixture realized in one-stage technology in a disc granulator were compared with the effects of two-stage agglomeration. During the research, a mixture (in a 1:1 ratio) of waste sulfogypsum and lime flour was used. Such a weight ratio provides maximum use of the sulfogypsum waste while maintaining good mechanical properties of the granulate. The granulated bed was moistened with a lignosulfonate solution. The process was carried out periodically. After the experiment, the grain composition of the granulate obtained was determined and tests were performed to determine the strength of the product. The test results were compared with analogous ones obtained during granulation with the use of molasses (waste from sugar production). The results obtained were verified during a trial carried out on an industrial scale.