Using The Gold Assaying Crucible
The fire assay method for gold is determine the content of precious metals quantitatively by smelting ores and metallurgical products with flux.In the arbitration analysis of gold and silver content,the fire assay method is usually used as it has high precision and accuracy of determination results,
The fire assay crucible has good temperature resistance, long-term use at 1300 ℃, short-term 1550 ℃, and good resistance to rapid cooling and heat, not easy to burst. Then we need to pay attention to the following points when using the test crucible.
1. The sample weighting
According to the complicated requirements of incoming samples, weigh and number them respectively. Add the clay crucible with some existing basic ingredients into it, and then add the required soluble starch (quasi-weight) and lead oxide according to the ingredients according to the sample classification and requirements, and then put it in the fume hood for full stirring.
2. Temperature warming then put into the furnace
When the temperature of the furnace rises to 750-900℃, turn off the power supply of the cabinet (to avoid damaging the silicon carbon rod), and put the clay crucible containing the sample into the furnace according to the number.When entering the furnace, turn off the switch first, then the power supply;After entering the furnace, close the furnace door, turn on the power switch, adjust the temperature to 750℃, and wait for 30 minutes when the temperature rises to 750℃;Then adjust the temperature to 1100℃, and wait for 20 minutes when the temperature rises to 1100℃.Continue to heat for 10 minutes.
Turn off the electric furnace, take the hot melt sample out of the furnace according to the number, pour into the iron crucible and let cooltes.
Take out the cool slag from the iron crucible, deduct the slag from the lead inside according to the number and knock it into a square for tweezers to pick up.
Weigh the buckle and count by number.