1. After the testing on adsorption of impurity by polyfoam and adsorption conditions, the ideal working condition was determined for the analytical instrument.

2. The polyfoam has the features of high absorptivity and stability for gold in the acid medium, and has become one of the important methods to concentrate free gold in the lab.

3. Polyfoam (Polystyrene), called EPS, is a kind of white foaming agent with air for filling material. One of materials using for packaging extensively.

4. This paper emphatically expounds the application of the method of polyfoam buried in shallow borehole to gold exploration.

5. The utility model relates preforming machine which relates to the field of polyfoam machines.