Heating selection is Petrov method or improved Petrov method for separation of scheelite and calcium minerals. Petrov method is invented by Professor Petrov of Michalis Noble Mineral Processing Institute of the Soviet Union in the early fifties.

Some scholars have come to the following understanding through laboratory research:

1. When separate scheelite, quartz and silicate gangue mineral, normal selection and heating selection can both get a good effect.

2. When separate scheelite and fluorite, heating selection has a better effect instead of normal selection.

3. When separate scheelite and calcite, normal selection and heating selection can not get an ideal effect , normal selection’s effect is even worse.

Normal selection takes a long time (40-60 minutes) and strong stirring in separation, and with repeate selections. But it’s still not as good as heating selection.

 

Beneficiation Research and Design Institute of the Soviet Union, "Michalis Noble" is a large-scale comprehensive scientific research and design institutions with as the main body of the professional beneficiation and sintering process equipment , belonging to non-ferrous metallurgy industry. The institute was founded on February 1920, the existing staff of 1900, including 7 Ph.D. of technical sciences, 70 licentiates of technical sciences. The current president of the Soviet Academy of Communication Sciences, Doctor of Technological Sciences, USSR State prize winner Professor Petrov.

 

Petrov method Introduction: Before scheelite Selection section, the concentration of 60% -70% of the crude concentrate was added a lot of sodium silicate for prolonged heating stirring, and diluted to a concentration of about 20% at normal temperature then selection. (add 20-60 kg of sodium silicate per tonne of dry ore, heating to about 90 degrees, holding the temperature more than half an hour)