Disclosed is an aluminum composite material including an aluminum alloy material containing magnesium, and a bonding material formed by brazing using a flux, the bonding material being adapted to bond the aluminum alloy material thereto. In the aluminum composite material, the bonding material contains a magnesium-containing compound other than KMgF.sub.3 and MgF.sub.2. The present invention provides an aluminum composite material with satisfactory brazeability to an aluminum alloy material containing magnesium, a heat exchanger including the aluminum composite material, and a flux suitable for use in braze.

Disclosed is an aluminum composite material including an aluminum alloy material containing magnesium, and a bonding material formed by brazing using a flux, the bonding material being adapted to bond the aluminum alloy material thereto. In the aluminum composite material, the bonding material contains a magnesium-containing compound other than KMgF.sub.3 and MgF.sub.2. The present invention provides an aluminum composite material with satisfactory brazeability to an aluminum alloy material containing magnesium, a heat exchanger including the aluminum composite material, and a flux suitable for use in braze.

A method for preparing zirconium boride and synchronously preparing a cryolite is provided which includes the following steps: Step A: placing aluminum in a reactor, heating the reactor to 700-850 degrees centigrade, and adding the mixture of fluorozirconate and fluoborate; and Step B: stirring the reactants for 4-6 hours and extracting the upper molten liquid to obtain a cryolite, wherein the lower substance is zirconium boride. The disclosure has the following beneficial effects: the new zirconium boride preparation method provided herein is simple in preparation flow and the device used, short in preparation period and high in reaction efficiency, the prepared zirconium boride with many contact angles has a large specific surface area and contains a controllable amount of aluminum.

A method for preparing zirconium boride and synchronously preparing a cryolite is provided which includes the following steps: Step A: placing aluminum in a reactor, heating the reactor to 700-850 degrees centigrade, and adding the mixture of fluorozirconate and fluoborate; and Step B: stirring the reactants for 4-6 hours and extracting the upper molten liquid to obtain a cryolite, wherein the lower substance is zirconium boride. The disclosure has the following beneficial effects: the new zirconium boride preparation method provided herein is simple in preparation flow and the device used, short in preparation period and high in reaction efficiency, the prepared zirconium boride with many contact angles has a large specific surface area and contains a controllable amount of aluminum.

Provided are a new phosphor having emission characteristics different from the conventional nitride or oxynitride phosphor, a manufacturing method, and a light-emitting device. In an embodiment, the phosphor may include inorganic substance having crystal represented by A.sub.26(D, E).sub.51X.sub.86 including at least A, D, X (A is at least one kind of element selected from Mg, Ca, Sr, and Ba; and D is Si, and X is at least one kind of element selected from O, N, and F); and further includes, if necessary, E (E is at least one kind of element selected from B, Al, Ga, and In) wherein the crystal further includes M (M is at least one kind of element selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb). Upon irradiation of excitation source, the maximum value of emission peak in a wavelength range from 630 nm to 850 nm may occur.

Provided are a new phosphor having emission characteristics different from the conventional nitride or oxynitride phosphor, a manufacturing method, and a light-emitting device. In an embodiment, the phosphor may include inorganic substance having crystal represented by A.sub.26(D, E).sub.51X.sub.86 including at least A, D, X (A is at least one kind of element selected from Mg, Ca, Sr, and Ba; and D is Si, and X is at least one kind of element selected from O, N, and F); and further includes, if necessary, E (E is at least one kind of element selected from B, Al, Ga, and In) wherein the crystal further includes M (M is at least one kind of element selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb). Upon irradiation of excitation source, the maximum value of emission peak in a wavelength range from 630 nm to 850 nm may occur.

Disclosed is a method for removing fluorine in a positive electrode leachate of lithium batteries, comprising: adding acid and an oxidizing agent to battery powder for leaching, and removing impurities from the obtained leachate to obtain a fluorine-containing solution; adding dawsonite to the fluorine-containing solution, and meanwhile adding sulfuric acid, stirring for reaction at a certain temperature, and performing solid-liquid separation to obtain fluorine-removed solution and filter residues; and washing the filter residues to obtain crude sodium hexafluoroaluminate. According to the present invention, the dawsonite is used for removing fluorine from waste lithium batteries, the dawsonite has good selectivity, does not react with nickel, cobalt, manganese, lithium and the like in the solution, and only reacts with fluorine ions in the solution, so that the purpose of selectively removing fluorine is achieved, and the loss of nickel, cobalt, manganese and lithium metals in the solution is avoided.

Disclosed is a method for removing fluorine in a positive electrode leachate of lithium batteries, comprising: adding acid and an oxidizing agent to battery powder for leaching, and removing impurities from the obtained leachate to obtain a fluorine-containing solution; adding dawsonite to the fluorine-containing solution, and meanwhile adding sulfuric acid, stirring for reaction at a certain temperature, and performing solid-liquid separation to obtain fluorine-removed solution and filter residues; and washing the filter residues to obtain crude sodium hexafluoroaluminate. According to the present invention, the dawsonite is used for removing fluorine from waste lithium batteries, the dawsonite has good selectivity, does not react with nickel, cobalt, manganese, lithium and the like in the solution, and only reacts with fluorine ions in the solution, so that the purpose of selectively removing fluorine is achieved, and the loss of nickel, cobalt, manganese and lithium metals in the solution is avoided.

The disclosure provides low-molecular-ratio cryolite for aluminum electrolytic industry, which consists of potassium cryolite and sodium cryolite with a mole ratio of 1:11:3, wherein the molecular formula of the potassium cryolite is mKF.AlF.sub.3 and the molecular formula of the sodium cryolite is nNaF.AlF.sub.3, where m=11.5 and n=11.5. When the low-molecular-ratio cryolite provided by the disclosure is applied to the aluminum electrolytic industry, electrolytic temperature and power consumption can be reduced and electrolytic efficiency is improved.

The disclosure provides low-molecular-ratio cryolite for aluminum electrolytic industry, which consists of potassium cryolite and sodium cryolite with a mole ratio of 1:11:3, wherein the molecular formula of the potassium cryolite is mKF.AlF.sub.3 and the molecular formula of the sodium cryolite is nNaF.AlF.sub.3, where m=11.5 and n=11.5. When the low-molecular-ratio cryolite provided by the disclosure is applied to the aluminum electrolytic industry, electrolytic temperature and power consumption can be reduced and electrolytic efficiency is improved.