FIELD: chemistry.
SUBSTANCE: invention relates to chemical industry. The method of producing thermal phosphoric acid involves preliminary thermal treatment of phosphorite, quartzite and coke, preparation of a mixture from said components at given ratio, where said mixture has acidity index of 0.76-1.0, and loading said mixture into furnace bins and then feeding through pipes into the bath of a phosphorus furnace, in which there are self-sintering electrodes. The completeness of the process of reducing phosphorus from the mixture is controlled by feeding fine coke and/or phosphorite into the reaction zone through the inner cavity of the self-sintering tubular electrodes, tapping slag and ferrophosphorus. Partial burning of the furnace gas containing phosphorus and carbon oxide in an air current is carried out under the furnace roof by feeding air. The remaining furnace gas is then fed for after-burning through loading pipes by creating optimum discharge in the gas passage. Pre-cooled phosphorus pentaoxide obtained during burning is fed for hydration to obtain phosphoric acid. Phosphoric acid is cooled. The gas is cleaned from acid mist in an electrofilter and then released into the atmosphere.
EFFECT: method and device enable to obtain cheap phosphoric acid without using high-quality phosphate raw material.
4 cl, 4 dwg, 1 ex
