Linatex gives Batts Combe the treatment.

Situated on the edge of Cheddar village, Batts Combe Quarry has been operating since the early 20^th century and is owned and operated by Hanson Aggregates. Currently processing 4000 tonnes of limestone per day, one third of which is supplied to an on-site lime kiln, the remainder is sold as coated or dusted aggregates. Recently the company has made a £1 million investment in a new washing plant. Designed to operate at a maximum of 500 tonnes per day the purchase and installation of the plant has been commercially driven and also provides the company with an increased level of health and safety within the site.

Commissioned in January 2005 the new wash plant has provided Hanson with the ability to sell quality materials to its local markets, previously only supplying scalpings the new plant produces a 20-5 material and a good quality sand. The 20-5 can be stocked or supplied to Hanson's own ready-mixed concrete plants; the production of sand has also benefited Hanson as this has allowed them to establish a new local market for this product.

Working closely with other suppliers Linatex installed a washing system. As with all crushed scalpings the sand gradings tend to be grit and silt. Linatex therefore treated the -5mm fraction by reducing the -75µ (silt) content to an acceptable level to produce a coarse concrete sand.

PROCESS.

The -5 mm underflow from the washing screen (up to 60 tonnes/hr with up to 53m³/hr of water) is discharged into a 2.1 m diameter Linatex feed-regulating sump. The overflow from this vessel which contains silt is piped to an in-ground effluent sump. The useful sand and water to form a slurry is pumped from the base of the unit to a Linatex HK 100 sand separator equipped with an extended feed box.

This separator ensures the capture of useful sand while removing the majority of unwanted -75 micron silts and clays in the overflow, which is discharged to the effluent sump. The underflow discharged by the HK 100 separator, is discharged on to a Linatex VD6 dewatering screen equipped with a polyurethane deck. This vibrating unit removes any remaining free water and discharges clean concrete sand (with a moisture content of around12% ) on to a cantilevered inclined stockpiling conveyor. The underflow from the screen is directed back to the feed-regulating sump to prevent the loss of useful material.

The silt slurry is pumped from the in-ground effluent sump to a waste sump where it is then fed to the thickener.

Linatex Ltd,
Wilkinson House,
Galway Road,
Blackbushe Business Park,
Yateley,
Hampshire GU46 6GE 
Tel: 01252 743016 
Fax: 01252 743030
Web: http://www.linatex.com/