DIATOMITE-BASED MULTIPURPOSE MATERIAL, PREPARATION PROCESS AND PRODUCTS MADE THEREFROM

The invention relates to a diatomite-based multipurpose material and to a process for preparing the same, to obtain filter additives, NPK fertilizers for soil treatment or for foliar treatments, for conditioning various microorganisms or for preparing phase-exchange materials for active thermal insulation. According to the invention, the material is presented as granules with sizes ranging between 2.2...8.4 mm with a permeability ranging between 0.25...2 darcy and it consists of the following components: 84.7...91.7% diatomite, 4.3...10.8% eggshells, 3.2...3.6% sodium alginate, 0.8...0.9% polyvinyl alcohol, the percentage being expressed by mass, and it has a content of < 500 mg/kg soluble calcium ions and < 80 mg/kg soluble iron ions. The claimed preparation process consists in extracting diatomite from the quarry, fragmenting the diatomite by crushing until reaching centimeter sizes, grinding the diatomite in a hammer mill in a hot air stream, at 140...180°C, separating sand and clay in pneumatic granule screening machines, delaminating in air stream, pneumatically concentrating and collecting powder < 20 μ m in bag filters, homogenizing and final grinding in a micronization plant followed by separating fractions with sizes > 20 μ m from those with sizes < 20 μ m and separately collecting them in cyclone-silos, mixing 5...10 kg of diatomite powder with sizes < 20 μ m with 1 m3 of solution with a content of 80 g of sodium alginate and 20 kg of polyvinyl alcohol, pulverizing 40... 45 l diatomite suspension in alginic acid and polyvinyl alcohol solution for 15 min, 45 sec every 3 min, for granulating a mixture of 84.25...91.5 kg of diatomite < 20 μ m and 4.3...10.8 kg of eggshells, on a granulating tray inclined at 40°, at a speed of 15...20 rpm, and drying the granules in a hot-air rotary dryer at a temperature ranging between 140...160°C. Invenţia se referă la un material multifuncţional pe bază de diatomită şi la un procedeu de obţinere a acestuia, pentru obţinerea aditivilor de filtrare, a fertilizanţilor NPK pentru tratamentul solului sau pentru tratamente foliare, pentru condiţionarea diferitelor microorganisme sau pentru obţinerea materialelor cu schimb de fază pentru termoizolaţii active. Materialul conform invenţiei se prezintă sub form ă de granule cu dimensiuni cuprinse între 2,2...8,4 mm cu o permeabilitate cuprinsă între 0,25...2 darcy şi este alcătuit din următoarele componente exprimate în procente masice: 84,7...91,7% diatomită, 4,3...10,8%