Rfefactory gold ore refers to gold ore that cannot be recovered satisfactorily by conventional cyanidation. Some reasons for the refractory gold ore, one is due to the fine gold particles (typically only a few microns) is physically wrapped pyrite or arsenopyrite minerals and other difficult to reach with the main leaching agent, one ore contains interference due to Cyanide substance. Accurate Weighing Machine ,Industrial Weighing Machine,Automatic Weighing Machine,Weight Weighing Machine Guangzhou Jiluo Machinery Manufacturing Co.,Ltd , https://www.gzjiluo.com
     For physically wrapped refractory ore, an effective method is to pretreat before cyanidation. The current pretreatment techniques for treating high arsenic and high sulfur refractory ores are:
     (1) Calcination: generally used to treat flotation gold-sulfur concentrate to facilitate cyanide leaching. The roasting equipment includes a reverberatory furnace, a rotary kiln, a boiling furnace, and the like. When the arsenic pyrite is treated, the arsenic in the ore is first converted into the arsenic trioxide volatilization by non-oxidative roasting, and then the oxidative roasting is performed to convert the sulfur into sulfur dioxide for discharge, and the gold is dissociated after roasting, which is favorable for cyanide leaching. The application of this method is limited due to the presence of sulfur dioxide in the roasting exhaust gas, but in recent years there have been some new plants.
     (2) Wet oxidation and pressurization: no matter how deep the gold is wrapped in pyrite and arsenopyrite and the fineness of gold, pressurized oxidation can oxidize and dissolve pyrite and arsenopyrite. Precipitate under certain conditions to dissociate the gold. This method has become the most effective method for dealing with refractory gold mines (excluding carbon) in the contemporary era. In recent years, several high-sulfur and high-arsenic large-scale gold mines that have been put into production in recent years have chosen this method.
     (3) Bacterial leaching: In essence, the As and Fe are oxidized and dissolved by bacteria to dissociate the gold, and then filtered, and the filtrate is neutralized to form a solid precipitate (FeAsO 4 Fe(OH) 3 ), and the filter residue is leached and recovered into the cyanide leaching solution. gold. The bacteria are mainly iron spores, sulfide spores, and thermophilic Thiobacillus.
     In 1986, the world's first bacterial leaching factory was built in the Fairview gold mine in South Africa. It is known that there are many mines using this technology abroad.
     In addition, methods such as Redox, Caro, and Cashman are still in different stages of development, but they have not reached the level of industrial application.