It is preferable that metallic sodium to be loaded to an engine valve used for an internal combustion engine such as automobile engine have high purity. However, conventionally, an organic solvent remaining in micropores on a surface of the metallic sodium have been hardly attracted attention. Provided is a method for purifying metallic sodium including steps of placing metallic sodium containing organic solvent in the micropores thereof in a melting tank which is sealed, and heating the melting tank under reduced pressure to vaporize and remove the organic solvent coating the metallic sodium.

It is preferable that metallic sodium to be loaded to an engine valve used for an internal combustion engine such as automobile engine have high purity. However, conventionally, an organic solvent remaining in micropores on a surface of the metallic sodium have been hardly attracted attention. Provided is a method for purifying metallic sodium including steps of placing metallic sodium containing organic solvent in the micropores thereof in a melting tank which is sealed, and heating the melting tank under reduced pressure to vaporize and remove the organic solvent coating the metallic sodium.

Processes for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof. Systems for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof.

Processes for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof. Systems for regenerating alkali process streams are disclosed herein, including streams containing sodium hydroxide, magnesium hydroxide, and combinations thereof.

The invention discloses a treatment method of a chlorine-containing zinc oxide secondary material, which comprises the following steps: 1) leaching the chlorine-containing zinc oxide secondary material I through an acid solution; 2) selectively extracting zinc through di-(2-ethylhexyl)phosphoric acid (P204)-kerosene solvent; 3) implementing stripping-electrolysis zinc recovery; 4) repeating steps 1)-4); 5) taking out the raffinate obtained from the Step (4), mixing the residual taken out raffinate with chlorine-containing zinc oxide secondary material II when balance on chlorine ion input and taking out is achieved; carrying out liquid-solid separation; leaching the separated deposit through acid raffinate of the step 1); 6) after separated solution achieves preset conditions, purifying the chlorine-containing aqueous phase; 7) evaporating and concentrating to crystallize out KCl and NaCl products. The invention is environment-friendly and energy-saving, and free from process wastewater emission; production cost is greatly reduced and secondary pollution of the current dechloridation process is eliminated thoroughly.

The invention discloses a treatment method of a chlorine-containing zinc oxide secondary material, which comprises the following steps: 1) leaching the chlorine-containing zinc oxide secondary material I through an acid solution; 2) selectively extracting zinc through di-(2-ethylhexyl)phosphoric acid (P204)-kerosene solvent; 3) implementing stripping-electrolysis zinc recovery; 4) repeating steps 1)-4); 5) taking out the raffinate obtained from the Step (4), mixing the residual taken out raffinate with chlorine-containing zinc oxide secondary material II when balance on chlorine ion input and taking out is achieved; carrying out liquid-solid separation; leaching the separated deposit through acid raffinate of the step 1); 6) after separated solution achieves preset conditions, purifying the chlorine-containing aqueous phase; 7) evaporating and concentrating to crystallize out KCl and NaCl products. The invention is environment-friendly and energy-saving, and free from process wastewater emission; production cost is greatly reduced and secondary pollution of the current dechloridation process is eliminated thoroughly.

Problem is to selectively and inexpensively recover a metal ion in a liquid. Solution is a metal ion recovery device, in which a permselective membrane for selectively permeating Li is used, and on both main faces of the plate-like permselective membrane, a mesh-like negative electrode and a positive electrode are formed, respectively. This structure is provided in a treatment tank, and in the treatment tank, the permselective membrane partitions between a stock solution containing a Li ion, and a recovery solution into which Li is recovered. As the permselective membrane, lithium nitride (Li.sub.3N), Li.sub.10GeP.sub.2S.sub.12, (La.sub.x, Li.sub.y)TiO.sub.z, Li.sub.1+x+yAl.sub.x(Ti, Ge).sub.2?xSi.sub.yP.sub.3?yO.sub.12, and the like, which are super lithium ion conductors, can be used.

Problem is to selectively and inexpensively recover a metal ion in a liquid. Solution is a metal ion recovery device, in which a permselective membrane for selectively permeating Li is used, and on both main faces of the plate-like permselective membrane, a mesh-like negative electrode and a positive electrode are formed, respectively. This structure is provided in a treatment tank, and in the treatment tank, the permselective membrane partitions between a stock solution containing a Li ion, and a recovery solution into which Li is recovered. As the permselective membrane, lithium nitride (Li.sub.3N), Li.sub.10GeP.sub.2S.sub.12, (La.sub.x, Li.sub.y)TiO.sub.z, Li.sub.1+x+yAl.sub.x(Ti, Ge).sub.2?xSi.sub.yP.sub.3?yO.sub.12, and the like, which are super lithium ion conductors, can be used.

A method for in situ solution mining of a mineral from an underground evaporite stratum using a set of wells in fluid communication with at least one mineral cavity with some wells operated in solvent injection mode and other wells operated in brine production mode and optionally with some inactive wells, comprising switching the operation mode of one or more wells. The evaporite mineral preferably comprises trona. The at least one cavity may be formed by directionally drilled uncased boreholes or by lithological displacement of the evaporite stratum at a weak interface with an underlying insoluble stratum by application of a lifting hydraulic pressure to create an interfacial gap. The extracted brine can be processed to make valuable products such as soda ash and/or any derivatives thereof. This method can provide more uniform dissolution of mineral in the cavity, minimize flow channeling, minimize sodium bicarbonate blinding for solution mining of incongruent trona ore, and/or may avoid uneven deposit of insolubles.

A method for in situ solution mining of a mineral from an underground evaporite stratum using a set of wells in fluid communication with at least one mineral cavity with some wells operated in solvent injection mode and other wells operated in brine production mode and optionally with some inactive wells, comprising switching the operation mode of one or more wells. The evaporite mineral preferably comprises trona. The at least one cavity may be formed by directionally drilled uncased boreholes or by lithological displacement of the evaporite stratum at a weak interface with an underlying insoluble stratum by application of a lifting hydraulic pressure to create an interfacial gap. The extracted brine can be processed to make valuable products such as soda ash and/or any derivatives thereof. This method can provide more uniform dissolution of mineral in the cavity, minimize flow channeling, minimize sodium bicarbonate blinding for solution mining of incongruent trona ore, and/or may avoid uneven deposit of insolubles.