A 1,200 Gauss continuous-duty magnetic separator is recommended for sorting construction waste containing metal: ferrous metal recovery efficiency of up to 98.7%, handles particle sizes of 0–400 mm, and has an optimal feed rate of 1.5–4 tonnes per hour per metre of width.
The hammers in a rotary crusher are turned every 800–1,200 hours; the interval depends on the raw material, the procedure takes 45–70 minutes, and regular checks for wear and clearances are required.
Standard crusher hammers process 8,000–12,000 tonnes of granite; their service life depends on the hardness of the rock and the presence of impurities. Regular maintenance increases the service life by 12%; manufacturers guarantee a minimum of 7,000 tonnes.
When crushing granite rather than limestone, the fuel consumption of the crushers increases by 28–42% due to granite’s higher resistance to crushing and its abrasiveness; for the fine fraction, there is an additional increase of 7–9%.
The actual productivity of mining equipment in quarries averages 78% of the stated figure, depending on the type of rock, maintenance and operating conditions; the stated figure is achieved in only 3% of cases.
When the crusher feed size is increased from 300 to 500 mm, throughput increases by 22%: linearly by 7% for every 60 mm up to 420 mm, after which the rate of increase slows down. These figures depend on the type of crusher, the material and the feed rate.
A medium-sized mobile cone crusher processes granite into a 5–20 mm size fraction at a capacity of 180–320 tonnes per hour; its performance is influenced by the hardness of the granite, the feed rate and the moisture content; There are various classes of crushers; maintenance every 200 hours ensures consistent performance.
When the limestone’s moisture content is 8–10%, the mobile crusher operates consistently at a throughput of 180–220 t/h, with a high yield of the target fraction and low downtime; compared with other moisture contents, these performance figures are optimal.
Rock crushers are indispensable in the mining industry; their price depends on the type and capacity. It is advisable to buy directly from reputable manufacturers to avoid mark-ups and to obtain a warranty.
Crushers with a capacity of 500 t/h for the mining and construction sectors cost between 3.2 and 18 million roubles (Russian-made); Western-made models are 40–60% more expensive. The price depends on the type, configuration and manufacturer; it is more cost-effective to buy directly from the manufacturers without intermediary mark-ups.
