铜跟硝酸汞发生置换反应后，被置换出的汞附着在粗铜丝的表面，用纸和砂纸清除，易造成环境污染和沾染皮肤而造成危害。如果先将细砂装入高型小烧杯中，适当按压细砂，使之紧实，做完实验后，将表面附着有汞的铜丝反复插入烧杯内的砂中多次，铜丝表面的汞就被细砂磨光，待汞生 After the replacement reaction of copper with mercury nitrate, the displaced mercury adheres to the surface of the thick copper wire and is removed with paper and sandpaper, which may cause environmental pollution and contaminate the skin and cause damage. If fine sand is put into a high-type small beaker first, fine sand is pressed appropriately to make it compact. After the experiment is finished, the copper wire with mercury attached on the surface is repeatedly inserted into the sand in the beaker several times. The surface of the copper wire is Mercury is polished by fine sand until mercury is produced