Phosphoric acid process
Номер патента: CA1129173A
Опубликовано: 10-08-1982
Автор(ы): Fernando N. Ore, James H. Moore, John D. Ellis
Принадлежит: Occidental Petroleum Corp
Опубликовано: 10-08-1982
Автор(ы): Fernando N. Ore, James H. Moore, John D. Ellis
Принадлежит: Occidental Petroleum Corp
Реферат: Abstract of the Disclosure Phosphate rock and sulfuric acid are reacted under conditions which result in the formation of calcium sulfate dihydrate and phosphoric acid of about 35% to about 55% P2O5. A two vessel reaction system is used in which the reaction slurry undergoes inter- and intra- vessel circulation. The solution portion of the slurry in the first vessel (the "dissolver") is preferably maintained at a negative sulfate concentration (i.e..excess Ca+2) and the solution in the second vessel (the "crystallizer") is pre-ferably maintained at a positive sulfate ion concentration. Also preferred is that the second vessel be maintained at a reduced pressure, (e.g. to provide evaporative cooling). Better filtration rates can thus be obtained due to the favorable shape, size and distribution of the dihydrate crystals. Most preferred is that a crystal modifier (e.g. a sulfonic acid, a sulfonic acid salt, tall oil fatty acids or esterified tall oil fatty acids) be present in the crystallizer. Surprisingly, the sulfuric acid used in the process can be less (e.g., 0.5 - 10%) than the stoichiometric amount to convert the calcium in the feed phosphate rock to calcium sulphate.
Integrated nucleic acid processing apparatus
Номер патента: US20220362780A1. Автор: Yang Liu,Song-Bin Huang,Chih-Yang Chen,Chien-Ting Liu,Jing GENG,Yen-You Chen,Po-Lin CHOU. Владелец: Delta Electronics Inc. Дата публикации: 2022-11-17.