Abstract: A method is disclosed for producing sulphate or phosphate-based fertilizer from hydrogen sulphide. The method involves feeding a stream containing a substantial volume of hydrogen sulphide and air to a furnace, where it is burned to produce a sulphur dioxide rich gas stream. The sulphur dioxide rich gas stream is then fed to a reactor to produce a sulphuric acid stream and a waste stream comprising carbon dioxide, nitrogen, oxygen, trace impurities and trace amounts of unreacted sulphur dioxide. The sulphuric acid stream is finally converted to a sulphate or phosphate-based fertilizer.

Abstract: According to a method of producing a phosphate fertilizer, a first portion of the phosphate is produced in a pipe cross reactor, and a second portion of the phosphate is produced in a pre-neutralizer. Both the first and second portions of the phosphate are supplied to a granulator. Ammonia is added to the granulator to react with the first and second portions of the phosphate. To produce the first portion of the phosphate, a micronutrient is added to phosphoric acid to produce an enriched acid, and the enriched acid and ammonia are added to the pipe cross reactor where they are allowed to react to produce ammonium phosphate.

Abstract: The new process is a process designed to produce P205 (the basic component in phosphoric acid, phosphate chemicals and fertilizers) in the gas phase in lieu of the state of the art (liquid phase) wet process. The new process is much less polluting than the wet process and much more energy efficient.

Abstract: dicalcium phosphate is prepared from phosphate rock by a process which comprises reacting phosphate rock with sulfur dioxide and an organic carbonyl compound for 0.5 to 10 hours while maintaining the temperature of the reaction mixture below 50.degree. C. The reaction yields a mixture of gangue, solid calcium .alpha.-hydroxy sulfonate and soluble dicalcium phosphate. The solids are separated from the liquid and P.sub.2 O.sub.5 values adhering to the solid are washed free with a mixture of carbonyl, water, and sulfur dioxide. The wash effluent is recycled to the process and both carbonyl and some sulfur dioxide are recovered from the filter cake by heating it. The offgas from the heated filter cake is recycled to the process and the dry filter cake, now largely calcium sulfite hemihydrate, is discarded.Dicalcium phosphate is precipitated from the reaction mixture filtrate in high yield by partially distilling sulfur dioxide from the filtrate.