PROBLEM TO BE SOLVED: To provide a treatment method of waste refuse incineration fly ash for reducing the content of hexavalent chromium or dioxins being a harmful substance contained in the waste refuse incineration fly ash and capable of forming a pellet hard to collapse. SOLUTION: The treatment method of the waste refuse incineration fly ash has a pellet granulation process for compounding powdery aluminum with the waste refuse incineration fly ash containing hexavalent chromium and granulating the waste refuse incineration fly ash to obtain the waste refuse incineration fly ash pellet and a reducing treatment process for heat-treating the waste refuse incineration fly ash at 800-1,500°C to reduce hexavalent chromium to trivalent chromium. COPYRIGHT: (C)2008,JPO&INPIT

Treatment method of waste refuse incineration fly ash

PROBLEM TO BE SOLVED: To provide a crystallization reactor apparatus for treating fluorine-containing raw water, which is capable of reducing the fluorine concentration in the treated water at low cost.SOLUTION: The crystallization reactor apparatus 5 for generation of calcium fluoride crystal via addition of slaked lime to fluorine-containing raw water includes a stirring means 20 with stirring blades 22, a crystallization reaction tank 12 for generation of calcium fluoride crystal via addition of slaked lime to raw water, a slaked lime adding pipe 22 for adding slaked lime to the vicinity of stirring blades 22, and an acid adding pipe 30 for adding acid, wherein the acid adding pipe 30 adds the acid to the raw water which is before being added to the crystallization reaction tank 12.

Crystallization reactor apparatus and crystallization reaction method

A process for removing fluorides from water, comprising a step of treating the water to be purified with calcium hydroxide in a concentration between 1.5 and 3 equivalents of calcium per equivalent of fluoride in which said water and said calcium hydroxide are agitated for a time between 45 and 120 minutes at a temperature less than 45°C, characterised by: 
a) adding a flocculating agent to the solution to sediment the sludge formed from Ca(OH) 2 and CaF 2 
b) separating from the solution a first sludge containing Ca(OH) 2 and CaF 2 in excess 
c) acidifying the solution until neutral pH is achieved 
d) adding to the remaining solution an Al compound to obtain a second sludge consisting of a poorly soluble compound of F and Al 
e) basifying the solution until a pH greater than 8.5 is achieved 
f) adding a flocculating agent to the solution 
g) separating said second sludge from the solution 
h) measuring the concentration of the fluorides in the residual solution and, if this concentration exceeds a predetermined value, repeating steps c) - h).

Process for removing fluorides from water

The invention discloses a process for removing fluorine in pickling waste liquid in steel and iron industry The process comprises the following technical steps: (a) adding a flocculant into the pickling waste liquid, stirring, flocculating and performing preliminary filtration to filter out solid impurities and oil; (b) adding an alkali into filtrate after filtration to regulate pH; (c) feeding a solution obtained in the step (b) into a heavy metal capturing device, and performing reaction on various heavy metal ions in the solution and a heavy metal capturing agent to form a heavy metal precipitate; (d) feeding a reactant in the step (c) into a filter to filter and recover the heavy metal precipitate, and keeping the filtrate for later use; (e) adding calcium chloride into the filtrate obtained in the step (d) to perform precipitation reaction and filtering a calcium fluoride product; and (f) adding active aluminum oxide into the filtrate to perform adsorption reaction and filtering to obtain water which fully meets national emission standard and can be recycled The method disclosed by the invention has the advantages of simple and convenient process, easiness in operation and low cost, and is suitable for industrial popularization and application

Process for removing fluorine in pickling waste liquid in steel and iron industry

The invention relates to a method for treating high-concentration nickel-containing wastewater by adjusting the pH value. The method comprises the following steps of: (1) adjusting the pH value of the wastewater to 7.5-8.5 by using sodium hydroxide, adding aluminium polychlorid, and stirring for 2-5 minutes, wherein the concentration of the added aluminium polychlorid is 400ppm; (2) adding sodium tripolythiocyanate, and stirring for 2-5 minutes, wherein the concentration of the added sodium tripolythiocyanate is 80ppm; and (3) adding an anion, stirring fully for 10-20 minutes, precipitating for 10-20 minutes, filtering and finally detecting the content of nickel in the wastewater, wherein the concentration of the added anion is 5ppm. By finding out the optimum pH value of the wastewater to remove nickel, the addition amount of drugs can be reduced, resources can be saved, and a better nickel removal effect can be achieved.

Method for treating high-concentration nickel-containing wastewater by adjusting pH value

PROBLEM TO BE SOLVED: To provide a method for treating fluorine-containing liquid waste, in which calcium fluoride and metal hydroxide, which are precipitated at a step of neutralizing fluorine-containing liquid waste containing a fluorine ion and a heavy metal ion, are separated from each other and the former is used satisfactorily in the iron industry as a slag formation promoting agent or an alternative raw material of fluorite being a raw material of hydrofluoric acid and the latter is used satisfactorily in the iron industry as a raw material for stainless steel. SOLUTION: The method for treating fluorine-containing liquid waste comprises the steps of: adding a calcium-containing substance to the fluorine-containing liquid waste containing the fluorine ion and the heavy metal ion to precipitate calcium fluoride-based particles (a particle precipitation step); adding a polymer flocculant to the calcium fluoride-based particle-precipitated liquid to produce flocks of calcium fluoride-based particles; and subjecting the flock-produced liquid to solid-liquid separation to recover calcium fluoride-based particles as a solid portion. A part of the recovered solid portion is returned at the particle precipitation step to further precipitate calcium fluoride on the precipitated calcium fluoride-based particles and increase the particle size thereof and the calcium fluoride-based particles having the increased particle size are recovered as the solid portion by the solid-liquid separation. COPYRIGHT: (C)2007,JPO&INPIT

Method for treating fluorine-containing liquid waste

PROBLEM TO BE SOLVED: To provide an elution suppression method of toxic heavy metals for soil or dust from which mercury or other heavy metals elute SOLUTION: Powder containing one or more kinds of metallic iron, metallic nickel, metallic aluminum and metallic zinc, and powder or liquid containing non-sulfate sulfur are charged to soil or dust from which mercury or other heavy metals elute, thereby mercury ions are reduced to metallic mercury to deposit the reduced mercury ion on surface layers of metallic iron, metallic nickel, metallic aluminum and metallic zinc, and stabilize it Heavy metals other than mercury, capable of forming sulfide are stabilized by forming sulfide Hexavalent chromium not forming sulfide is reduced to trivalent chromium and stabilized by forming chromium hydroxide (III) COPYRIGHT: (C)2006,JPO&NCIPI

Ono Nobuyuki

Papers

Method for treating fluorine-containing liquid waste

Elution reduction method of heavy metal