An innovatory approach for determining grinding media system to optimize fraction compositions of grinding products based on grinding dynamics principle

Abstract

An innovatory approach for determining grinding media ratio and sizes to optimize fraction compositions of grinding products was created based on the principle of grinding dynamics by the single fraction tests, which were conducted with the ore from Yongping Copper mine (China) in a discontinuous conical ball mill (D × L 360 × 160 mm, China), and the results show that the optimal ball size for +8 mm fraction, −8 + 5 mm fraction, −5 + 0.45 mm fraction and −0.3 + 0.2 mm fraction are Φ70 mm, Φ60 mm, Φ50 mm and Φ30 mm, respectively. Furthermore this approach was supported from the point of view of collision energy between ore and media by discrete element method (DEM), wtih results illustrating that the materials are more active with the highest tangential collision energy with 2.23 J. In addition, the comparable tests of the full fraction feed were conducted with media system determined by this method, with the grinding technical efficiency 71.71%, being 7.61 and 1.63 percentage points higher than that under the scheme on site and the other scheme. Furthermore, applicability and feasibility were proved to be tremendously positive through the industrial tests, and results of industrial tests show that unit media consumption and unit energy consumption are reduced by 0.56 kW·h and 0.072 kg/t, respectively, what's more, not only the production capacity is promoted by 1.04 t/h, but also concentrate indexes are also improved with grade and recovery being increased by 1.01 and 2.61 percentage points compared with that before the test. This method is extremely promising and novel and could be used in most beneficiation plants to optimize the media system of ball mill to elevate indexes and promote production in all probability.