At present, the pyrolysis equipment for producing ammonium metatungstate is mainly rotary calciner, which is a rotary kiln. A rotary kiln is a pyroprocessing device used to raise materials to a high temperature (calcination) in a continuous process. The kiln is a cylindrical vessel, inclined slightly to the horizontal, which is rotated slowly about its axis. The material to be processed is fed into the upper end of the cylinder. As the kiln rotates, material gradually moves down towards the lower end, and may undergo a certain amount of stirring and mixing. Hot gases pass along the kiln, sometimes in the same direction as the process material (co-current), but usually in the opposite direction (counter-current). The hot gases may be generated in an external furnace, or may be generated by a flame inside the kiln. Such a flame is projected from a burner-pipe (or "firing pipe") which acts like a large bunsen burner. The fuel for this may be gas, oil, pulverized petroleum coke or pulverized coal.
alkali decomposition furnace |
plate and frame filter |
Ammonium metatungstate produced by ion exchange method will probably use ion exchange resin, crystallizer, or spray dryer and other production equipments. Alkali decomposition furnace is mainly used for decomposing tungsten ore during the preparation of AMT to dissolve tungsten into a solution. A plate and frame filter press is the most fundamental design, and many now refer it as a "membrane filter plate". This type of filter press consists of many plates and frames assembled alternately with the supports of a pair of rails. It is used for the impurity removal process of sodium tungstate for preparing high purity sodium in the APT preparation.
ion exchange column |
spray drying tower |
Ion exchange colum is used for removal of S, Mo, P, As, Ca, Cu and Sn and other impurities. Co-current deionization refers to the original downflow process where both input water and regeneration chemicals enter at the top of an ion exchange column and exit at the bottom. Co-current operating costs are comparatively higher than counter-current deionization because of the additional usage of regenerants. Because regenerant chemicals are dilute when they encounter the bottom or finishing resins in an ion exchange column, the product quality is lower than a similarly sized counter-flow column. Spray drying is a method of producing a dry powder from a liquid or slurry by rapidly drying with a hot gas. This is the preferred method of drying of many thermally-sensitive materials such as foods and pharmaceuticals.
Chinatugnten Online Tel:86-592-512-9696 Fax:86-592-512-9797 Email:sales@chinatungsten.com
没有评论:
发表评论