Refractory gold concentrate microwave irradiation pretreatment
 With easy to handle gold resources dwindling , refractory gold processing method research increasingly important .
     According to the identification, gold intractable for the following reasons : ① physical package , ② chemical parcel , ③ covered gold , ④ gold cyanide in the presence of substances consumed , ⑤ carbonaceous material existence , ⑥ formed during roasting cover film , ⑦ formed during leaching minerals , ⑧ dip fusion gold compounds , ⑨ Others [ " " ] .
  Because of the specificity of substance , microwave heating or cause to minerals in the ore or chemical change in the phase , rather than directly affecting other minerals , therefore , difficult to process using conventional methods of minerals, by microwave irradiation may become good deal .
K.E.Haque In a typical refractory gold concentrate containing arsenic pyrite pretreatment , the application of microwave energy . When these refractory minerals microwave decomposition , Kim along with arsenic and sulfur is separated from the mineral matrix , so that travel
Gold can be used from a conventional alkaline cyanidation leaching . Experiments show that more than 80% of As and S in the form of volatile As2O3 and SO2 out, and most of oxidized iron Fe2O3, all Waldo stay in France for conventional alkaline cyanide leaching calcine , gold and silver leaching rates were 98% and 60%.
 K.E.Haque experimental results also showed that in the presence of NaOH in the case when the gold concentrate containing arsenic pyrite microwave irradiation pretreatment, avoiding the generation of As203 and Sq, calcine after pretreatment with cyanide France after leaching gold leaching rate of 99% , 70% silver .
 With conventional roasting method compared to the firing time of microwave irradiation and requirements ore has shown advantages. It conventional roasting pyrite gold concentrate containing arsenic needs 2h-2.5h, while the microwave irradiation is about 15min microwave radiation pretreatment gold when neither fuel nor the need to control sulfur in gold critical content .
In order to understand from the gold particles , it is common practice for finely ground (a 200 mesh or finer ) . But grinding to a 200 mesh , the cost is very expensive . Because microwave irradiation for roasted ore particles larger solution (a 10 mesh ) , so it saves costs in
With respect, especially in the grinding operation, there are obvious economic benefits