The biggest advantage of the automatic melting machine fusion method

It is understood that the average design maximum temperature of the fully automatic melting machine is 1500 degrees Celsius, and the maximum operating temperature is 1200 degrees. For carbonate, silicate, bauxite samples, a melting temperature of 1000 degrees Celsius is sufficient. The melting machine is mainly divided into three types: high-frequency induction melting machine, electric heating melting machine and gas melting machine. Typical sample types include oxides, sulfides, silicates such as mining ores, metallurgical ores, concentrates, etc. The melting machine uses the glass melting method to prepare glass melts. It is a sample preparation instrument for AAS, ICP, and X-fluorescence analysis. It basically eliminates the mineral effect and the enhanced absorption effect of the matrix, and has high measurement precision and good accuracy; the heating methods used for high-temperature melting are: gas heating, resistance radiation heating and high-frequency induction heating.
The melting process of the melting machine has two functions, one is to decompose the sample, and the other is to enrich the precious metals in the sample into the capture agent (i.e., the assay button). Generally, the melting point of the sample is very high and it is not easy to melt. Only after adding appropriate flux can it be melted at a lower temperature, and the metal in the sample is exposed and contacts the added collector. It is captured in the assay button.                     

The added chemical reagent is determined according to the properties of the sample, that is, the flour method, iron method and saltpeter method are used for high-temperature smelting, and the reduction of lead oxide is controlled by oxidizing agent or reducing agent during the melting process.

Maybe many friends don’t know that the biggest advantage of the melting method of the melting machine is that it can overcome the particle size effect and mineral effect in the sample. Due to the dilution effect of the solvent, it can also effectively reduce the absorption enhancement effect between elements. The melting machine uses lithium tetraborate for melting. The melting speed is fast and easy to use. The sample preparation methods of some common samples are summarized. That is, flux and demolding agent:

Lithium tetraborate is generally used as the flux. Because lithium tetraborate has a high melting point, it is generally added with lithium metaborate and lithium fluoride to reduce the melting point of the flux and enhance fluidity. In order to facilitate the removal of the melt from the crucible mold, a demolding agent should be added during the melting. The mold release agent is generally NH4Br, BrLi, NH4I, KI, etc., which are prepared into a supersaturated solution or used directly.
During the melting process, some harmful metal elements and As, Pb, Sn, Sb, Zn, Bi, S, Si, C, etc. will form alloys with platinum at high temperatures and corrode the crucible. For samples such as sulfides and metals, oxidants should be added for sufficient pre-oxidation.