The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

An economical method for recovering phosphate or phosphate and nitrogen from liquid streams. A liquid containing phosphate is introduced into a culture of autotrophic microorganisms in the presence of natural or artificial light, thereby producing a liquid effluent with elevated pH and reduced alkalinity. The alkalinity is reduced through the consumption of bicarbonate/carbonate by the autotrophic microorganisms. The effluent is then chemically treated with low-cost chemicals to provide Ca.sup.++ or Mg.sup.++ ions necessary to form a phosphate precipitate such as calcium phosphate or magnesium-ammonium-phosphate (MAP). The autotrophic microorganisms can be cultivated in ponds, lagoons, or photobioreactors. The pH of the culture is adjustable within a preferred range of 7.5 to 10.5 by adjusting the photobioreactor operation. The process includes an economical flotation separator for solid, liquid, gas separation and a means of concentrating ammonia nitrogen that may also be removed during the process of phosphate reclamation.

An economical method for recovering phosphate or phosphate and nitrogen from liquid streams. A liquid containing phosphate is introduced into a culture of autotrophic microorganisms in the presence of natural or artificial light, thereby producing a liquid effluent with elevated pH and reduced alkalinity. The alkalinity is reduced through the consumption of bicarbonate/carbonate by the autotrophic microorganisms. The effluent is then chemically treated with low-cost chemicals to provide Ca.sup.++ or Mg.sup.++ ions necessary to form a phosphate precipitate such as calcium phosphate or magnesium-ammonium-phosphate (MAP). The autotrophic microorganisms can be cultivated in ponds, lagoons, or photobioreactors. The pH of the culture is adjustable within a preferred range of 7.5 to 10.5 by adjusting the photobioreactor operation. The process includes an economical flotation separator for solid, liquid, gas separation and a means of concentrating ammonia nitrogen that may also be removed during the process of phosphate reclamation.

The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

An ammonia chemical species desorption process desorbs ammonia chemical species adsorbed onto a Prussian blue derivative more simply at lower cost under milder conditions as compared with using an aqueous solution of a salt or strong acid, and only water. This ammonia chemical species desorption process includes an ammonia chemical desorption step of bringing carbon dioxide and water into contact with a Prussian blue derivative represented by the following general formula (1), thereby desorbing an ammonia chemical species.
A.sub.xM[M(CN).sub.6].sub.y.Math.zH.sub.2O(1)
where x is 0 to 3, y is 0.1 to 1.5, z is 0 to 6, A is at least one cation of hydrogen, ammonium, an alkaline metal, and an alkaline earth metal, and M and M are each independently at least one cation of at least one of atoms having atomic numbers 3 to 83 except for ammonium, an alkali metal, and an alkaline earth metal.

An ammonia chemical species desorption process desorbs ammonia chemical species adsorbed onto a Prussian blue derivative more simply at lower cost under milder conditions as compared with using an aqueous solution of a salt or strong acid, and only water. This ammonia chemical species desorption process includes an ammonia chemical desorption step of bringing carbon dioxide and water into contact with a Prussian blue derivative represented by the following general formula (1), thereby desorbing an ammonia chemical species.
A.sub.xM[M(CN).sub.6].sub.y.Math.zH.sub.2O(1)
where x is 0 to 3, y is 0.1 to 1.5, z is 0 to 6, A is at least one cation of hydrogen, ammonium, an alkaline metal, and an alkaline earth metal, and M and M are each independently at least one cation of at least one of atoms having atomic numbers 3 to 83 except for ammonium, an alkali metal, and an alkaline earth metal.

The present disclosure relates to the field of tungsten smelting, and in particular to a leaching method of scheelite, and provides a new technology that scheelite is leached in low temperature with a mixture acid of sulfuric acid and hydrochloric acid or nitric acid and hydrochloric acid, calcium is precipitated incompletely, and then the acid leaching solution is regenerated and closed-circuit recycled is provided. The new technology is able to leach scheelite sufficiently in low temperature so as to improve the recovery rate of tungstate and decrease the requirement of equipment. As well, the inner wall of the reaction kettle, the heating pipe and the temperature measuring device are made of steel lined tetrafluoro material which has high acid corrosion resistance and is able to deal with scheelite with high fluorine, resists the corrosion of HF.

The present disclosure relates to the field of tungsten smelting, and in particular to a leaching method of scheelite, and provides a new technology that scheelite is leached in low temperature with a mixture acid of sulfuric acid and hydrochloric acid or nitric acid and hydrochloric acid, calcium is precipitated incompletely, and then the acid leaching solution is regenerated and closed-circuit recycled is provided. The new technology is able to leach scheelite sufficiently in low temperature so as to improve the recovery rate of tungstate and decrease the requirement of equipment. As well, the inner wall of the reaction kettle, the heating pipe and the temperature measuring device are made of steel lined tetrafluoro material which has high acid corrosion resistance and is able to deal with scheelite with high fluorine, resists the corrosion of HF.

The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

Disclosed is a process for co-manufacture of ACRN and HCN with improved HCN selectivity and reduced solids formation in a shared product recovery section.