Abstract: The present invention relates to an amorphous, vitreous phosphorus-potassium fertilizer obtained by melting raw materials containing phosphorus pentoxide (P2O5), potassium oxide (K2O), providers of SiO2 and silicates, and providers of MgO and CaO. The fertilizer of the present invention is produced by a process of melting the raw materials, followed by quenching, enabling the formation of a vitreous and amorphous material containing phases of phosphorus and of potassium, which are soluble in a weak acid.

Abstract: An angular abrasive proppant comprises angular sintered particles of a material selected from bauxite, clay-minerals, and mixtures thereof, with particle sizes varying from 30 mesh to 150 mesh. A process for the production of an angular abrasive proppant comprising sintered particles of a material selected from bauxite, clay-minerals, and mixtures thereof comprises the steps of drying, grinding, pelletizing, and sintering a bauxite starting material, grinding the sintered pellets, and sizing said particles to a particle size varying from 35 to 150 mesh. A hydraulic fracturing process uses as proppant the angular abrasive proppant as the described above.

Abstract: The present invention relates to an amorphous, vitreous phosphorus-potassium fertilizer obtained by melting raw materials containing phosphorus pentoxide (P2O5), potassium oxide (K20), providers of Si02 and silicates, and providers of MgO and CaO. The fertilizer of the present invention is produced by a process of melting the raw materials, followed by quenching, enabling the formation of a vitreous and amorphous material containing phases of phosphorus and of potassium, which are soluble in a weak acid.

Abstract: The present invention relates to a proppant for the hydraulic fracturing of oil or gas wells, which consists of a mixture of from 10 to 95% by weight of a spherical proppant and from 5 to 90% by weight of an angular material, the percentages being based on the total weight of the mixture. The proppant obtained according to the present invention is useful for eliminating or decreasing the “flow-back” phenomenon in operations in oil or gas wells.