Commonly used equipment in fire assay
(1) Trial furnace and ash blowing furnace
The high-temperature soot-blowing furnace used for testing is generally called the muffle furnace. The materials from various countries have been introduced to a certain extent and have certain technical requirements. The literature pointed out that "ash-blowing furnace—a muffle furnace type furnace. This furnace should have air inlets and outlets for air circulation, and it is best to preheat the air and make it pass stably. The furnace temperature can be evenly heated from room temperature to 1100 ℃. According to the information, the test furnace used in its laboratory can be completed at one time when placing the cupel, and the same is true for placing the lead button in the cupel. After the ash blowing is completed, all the cupel can be take it out all at once.
(2) Balance and weight
The fire assay method is a quality analysis method, which has strict requirements on the assay balance. The early Japanese double-arm swing-type gold test balances had a maximum weighing of 1-2g, which had stricter requirements for weights, which were made of platinum-iridium alloy. Assaying and analysis laboratories in all parts of my country use precision analytical balances weighing 20g and a sensitivity of 0.01mg. Many units have used precision analytical balances with a sensitivity of 0.001mg. Balances and weights require frequent calibration. According to the workload, the calibration cycle should be one month or one quarter.
(3) Divide the golden basket
Each country has specific regulations for the gold-sharing baskets dedicated to assay analysis. Japan uses platinum or porcelain plates; the former Soviet Union uses platinum; India uses platinum or quartz frames, which are composed of many small sleeves. These small sleeves are porous platinum cups based on platinum frames or fused silica frames. Porous fused silica cups; my country’s assay chamber is made of platinum or stainless steel plates.
(4) Cupel machine and tablet mill
Most of the domestic and foreign countries have not made clear requirements for the cupel machine and the flake grinding machine, but it is required that the forming pressure of the cupel should be consistent when making the cupel, and the gold and silver alloy sheet should be formed uniformly during the grinding to avoid the increase of analyze the error.