An On-stream size measuring equipment has been developed for flotation pulp. It uses both vibrational output and light absorption. Sample flows into the vibration detection cell and next into the light absorption cell.
The vibration pickup detects very weak signals that are produced by collisions of particles and the cell. Effective signals are separated through an acoustic filter from noises.
The cross section area of light absorption cell is 1.3 cm² and light pass length is 3 mm. Suitable pulp density for this cell is about 4 wt%.
Several kinds of closed circuit tests have been done using SiO₂ and complex sulphide ore particles. From these tests the following results were obtained.
1) When n value of Rosin-Rammler distribution function of samples remained nearly constant, it is possible for this equipment to measure the size distributed samples as well as size sorted samples
2) When the variation of pulp density is limited in narrow range, an on-stream size measurement is attainable by the vibrational output only.
At the pilot plant tests, -200 mesh% of flotation pulp were measured by this equipment. The results of on-stream measured size, compared with screen analysis, were as follows.
Number of samples 109
-200mesh%(mean value) 73.91%
Mean square root error 2.03%
Correlation coefficient 0.923