Abstract:

In order to improve the treatment capacity of a concentrator in Anhui Province，two differ⁃

ent schemes of high pressure roller mill system optimization test were carried out with medium crushing

products with total iron grade of 35.17% as samples.All the medium crushing products were pre-screen⁃

ing-screened onsize dry separation-roll mill test. The pre-screening test results of different sieve sizes

showed that the less the fine particle size in the ore feeding，the more favorable it was for the new genera⁃

tion of -5 mm particle size products. When the pre-screening sieve size was 5 mm，the content of the newly

generated -5 mm particle size was the highest，up to 57.99%.The high-pressure roller mill test results of

pre-screening of middle crushing products-dry separation of screened onsize products combined with un⁃

screened ore feeding show that with the decrease of the separation ratio of middle crushing products，the con⁃

tent of -5 mm particle size in roller feeding decreases，and the content of newly generated -5 mm particle

size increases. When the ore separation ratio is 3∶1，the content of the newly generated -5 mm fraction is

the highest，which is 45.36%.The comparison of test results shows that the test scheme of all pre-screening

screened onsize dry separation-roll grinding has the best index. Compared with the medium crushing prod⁃

uct directly subjected to high-pressure roll grinding，the content of the newly generated -5 mm fraction is

increased by25.47percentage points.

Key words:

high pressure roller mill, pre-screening, dry separation, magnetite