China-based Hunan Yan Run Construction Engineering Ltd specialises in preparing land for real estate construction, rock blasting and aggregates supply, both from construction site materials and quarried limestone. The company recently upgraded its crushing and screening plant to a modern, versatile and highly productive solution, combining a Sandvik QI442 HS impact crusher with a Sandvik QA335 Doublescreen.
The new crushing and screening plant has to meet certain requirements. It needs to accept a feed size of around 500 mm and produce highly accurate fractions (0-5 mm, 5-10 mm, 10-20 mm, and 20-31.5 mm) at a constant production rate of 200-250 t/hr. This machine combination was supplied to Yan Run by POTA Environmental Technology Co Ltd, a local authorised distributor for Sandvik mobile crushers and screens.
POTA recommended the Sandvik QI442 HS tracked impact crusher with a modular hanging screen unit, and also the QA335 Doublescreen. These machines provide Yan Run with a mobile crushing and screening solution with the highest environmental credentials, plus features that would enable highly productive and profitable use.
The Sandvik QI442 HS impactor (and QA335, which is part of Sandvik’s Doublescreen range of tracked screeners) supplied to Yan Run came equipped with a range of customer-focused features. A pre-screen is fitted to ensure maximum scalping capability and to prevent any undersize material passing through the impactor, leading to maximised throughput and reduced wear costs. This also allows a specific sized product to be produced from the natural fines conveyor.
The pre-screen has a choice of grizzly or punch plate top deck and mesh bottom, giving the flexibility to suit any application with the underpan feeder drastically reducing spillage generally associated with impact crushers. The crusher’s CI621 Prisec impactor, which comes with a host of innovations for improved efficiency and greater safety during maintenance, provides the ability to operate in either primary or secondary crushing modes.
Additionally, the two hydraulically assisted curtains can be readily adjusted to produce a wide range of high-quality product sizes.
Another major benefit incorporated into the QI442 HS model is the modular hanging screen system. This is interchangeable and offers the flexibility for the crusher to operate in open or closed circuit. The hanging screen option delivers multi-functionality as a 1, 2 or 3-way split screener, as well as operation as a highly productive and efficient impact crusher.
The double-deck hanging screen enables the QI442 HS to produce two screened products and recirculate the oversize back into the feed conveyor. The oversize conveyor may be hydraulically rotated for material stockpiling (90°) of up to three products on the floor, or removal (180°). The tail section can be raised hydraulically to give improved ground clearance for transport when loading or unloading.
Combined with the Doublescreen action of the QA335, Yan Run now has the capability to produce highly accurate gradings and fractions in one swift and effective process.
Both models are fitted with Sandvik My Fleet remote monitoring system as standard. This function has been developed to help customers know exactly how their equipment is being utilised. Through the collection and accurate monitoring of a wide array of parameters, the system facilitates accurate production forecasting and in turn ensures that the most efficient use is obtained from the equipment.
Since commissioning (by POTA technicians who continue to support Yan Run in the field), the Sandvik crushing and screening combination has consistently worked at 250 t/hr, producing the required fractions accurately. The machines can be maintained and serviced easily, thus minimising downtime whilst making them versatile to deal with any unexpected requirement.