Industrial demand for hexafluorosilicic acid (H2SiF6) is often lower than the amount produced from fluoride recycling processes. One alternative for using this surplus is manufacturing a soil conditioner by neutralizing the hexafluorosilicic acid with calcium oxide (CaO) inside an open, Kullman type reactor. The reaction ensures alkalinity to the soil conditioner having a pH of about 10, moisture less than about 40%, phosphorus (P2O5) at about 2.5%, calcium at about 22%, about 0.5% magnesium, about 10% silicon (about 30% to 40% water-soluble), about 18% fluoride, neutralization power of about 5% to 15%, and total neutralization power of about 5% to 12%. The resulting product, called AgroSiCa, is easily manageable with very high contents of Ca and Si (total and soluble), and also contains Mg, P, Fe, Zn, and F. When applied to soil, it contributes to the supply of nutrients, provides a better root growth and improves the plants development.