Rare earth ore dressing agent

(1) Collector The research and application of flotation reagents for rare earth minerals can be divided into three stages.

Research and application of oleic acid based collector is the first stage, due to the low selectivity of oleic acid, the mineral composition can be applied to a relatively simple ore, and is mainly used in the flotation of bastnaesite.

Research and application of chelating hydroxamic acids collector of the second stage, which is a copper oxide mineral (malachite and chrysocolla), wolframite, perovskites, cassiterite, iron oxide ore, apatite, A good collector for pyrochlore and rare earth minerals.

The third stage is the research and application phase of efficient, new collectors. One of the most important reasons is that it is difficult to separate the two minerals in the mixed rare earth concentrate of bastnasite and monazite because their density, specific magnetic susceptibility, dielectric constant and floatability are very close. This is the case with the Baiyun Obo rare earth mine in China.

At present, the collectors of rare earth minerals mainly include oleic acid, phosphonic acid or phospholipids, alkylsulfonic acids, hydroxamic acids, 802, 804 and H894.

(2) The modifier adjuster includes an activator of a rare earth mineral, an inhibitor of a non-rare earth mineral (and a pH adjuster).

1 Activator Rare earth mineral activator is mainly sodium fluorosilicate , its main role is three: cleaning rare earth mineral surface oxidation film and adhered slime, restore its pure surface, inhibit silicate minerals, enhance the surface of rare earth minerals The activity of the collector.

Since the optimal flotation pH of rare earth minerals is between 8.5 and 9.5, the dissociation and hydrolysis of sodium fluorosilicate at this time are carried out according to the following formula:

Many of the ions and molecules produced by the above reactions have an inhibitory effect on quartz , feldspar and other silicate minerals.

2 Inhibitors Silicate minerals are the main minerals associated with rare earth minerals, and water glass is a potent inhibitor. It not only inhibits silicate minerals. It also inhibits rare earth minerals and iron minerals. However, in moderately alkaline media (pH = 8.0 to 9.5), rare earth minerals have the highest floatability, while other minerals have poor floatability, thereby achieving effective inhibition. The main application indicators of water glass in the flotation of rare earth minerals are:

a. The active ingredient content, that is, the total content of xNa2O and ySiO2, generally 40% to 50%;

b. Modulus, ie m=SiO2/Na2O (when rare earth flotation, m=2.0~3.0.

(3) When the oleic acid and the alkyl hydroxamic acid are used as the collector of the rare earth mineral, since the foaming agent itself has strong foaming property, it is not necessary to add a foaming agent. With the application of the new collectors H205 and H894, new, highly efficient, nonionic surfactant foaming agents such as 210, J102, H103, etc. have emerged.

(1) Extraction of rare earth from ion-adsorbed ore by NaCl is one of the main chemical beneficiation methods for treating this type of ore. The ore transported from the stope is sent to a rectangular cement tank for immersion. The leaching solution is discharged from the discharge port through the filter layer at the bottom of the tank. The leaching residue is manually removed, and the leaching solution is precipitated in a saturated oxalic acid solution. After filtration, the filtrate is filtered through lime. Neutralize and add salt to return and reuse; the filter cake is rare earth oxalate, which is mixed with rare earth oxide by burning, washing with water and then burning. The main problem currently existing in this process is that the leaching residue contains high NaCl and causes soil salinization.

(2) Ammonium sulfate method The extraction of rare earth from ion-adsorbed ore with (NH4)2SO4 is a successful method in recent years. The difference from the NaCl method is that the ore is immersed in a solution of 1% to 2% of (NH4)2SO4, followed by precipitation with oxalic acid to obtain a rare earth oxalate, and then a single mixed rare earth containing REO>90% can be obtained by one burning. The oxide is returned to the filtrate by addition of ammonium sulfate. Compared with the NaCl method, the leaching residue does not cause soil salinization problems.

Water Works Valves

RSF Valve is a leading manufacturer of water works valves, our water works valves production line includes ductile iron Resilient Seat Gate Valve, ductile iron Metal to Metal Seat Gate Valve, ductile iron metal to metal seat swing Check Valve , ductile iron resilient seat swing check valve, ball check valve, dual plate check valve, ductile iron nozzle check valve, ductile iron globe valve, Y type strainer and T type strainer, etc.