About Derrick. 
For 70+ years, Derrick Corporation has been leading the industry in the design and manufacture of patented high-frequency vibratory screening machines and screen surfaces. With a pioneering spirit driving innovative solutions, Derrick is continuously in the forefront advancing the field of fine particle and solid-liquid separation technology.

Known worldwide for their high-capacity and superior separation efficiency, Derrick products allow processors to screen a wide variety of wet or dry fine materials in the range of 6.2 mm to 45 µm. Derrick’s global family, comprising of employees, sales representatives, and distributors, are strategically positioned worldwide to provide superior service and technical support.

New Technology, SuperStack

Derrick has once again redefined high capacity, high efficiency, fine particle wet screening with the introduction of the SuperStack. With 8 decks operating in parallel, 35% increase in the effective width of each deck, and innovative Front-to-Back tensioning system ensures ease of operation and rapid screen changes. The SuperStack has a demonstrated capacity up to 3 times that of the best fine screens currently available.

All of this added capacity comes with only a slight increase in the space required per machine, significantly reducing the total capital and installation cost as well as OPEX for any screening installation. The SuperStack is built to last and backed by a worldwide support team available 24/7.

Super Stack and Stack Sizer in Mill Circuit

The mill circuit is the largest contributor to energy consumption on most metallurgical plants treating base metal ores (copper, cobalt, zinc, tin, lead, nickel, etc.). This is typically between 50% and 80% of the total power consumption of a modern process plant.

A key consideration in milling operations is to liberate the valuable mineral species and optimise the pulp density for the downstream operations. Mill-Classifier must be regarded as a single unit operation when operating in closed circuit. By replacing the ubiquitous cyclone cluster with Stack Sizers or Super Stack screens, additional capacity is created, improved mineral recovery is evident with a simultaneous reduction in power consumption.

For example, a Peruvian copper/lead client have seen an increase of more than 75% in mill throughput by replacing their cyclones with the screen as indicated in below flow diagrams. Due to higher screening efficiency, overgrinding was minimized, and the circulating load dropped to about 60% with Stack Sizers® from initial 350% with cyclones.

The slime content (particles below 10 microns) in the flotation feed was reduced from 18% to 10%, resulting in significant increase in metal recovery. Results from 16 recent case studies where Derrick Stack Sizers® were installed yielded payback times from two to seven months based on before and after audits, replacing cyclones with Stack Sizers. The case studies range in application and includes iron ore, base metals, precious metals, and phosphates. Several applications in copper exist and are available upon request. Below flow diagrams is from case study 220.

Derrick Testing Laboratory

Derrick can provide high level modelling of the mill-cyclone vs mill-screen performance. Derrick in Buffalo New York USA is also well equipped with a laboratory and full-size pilot plant with the ability to test various types of material both wet and dry on full size screens to determine machine capacity and screening efficiency. There is no charge for testing, sample shipping is only responsibility of the customer.

The Derrick test facility is an integral part of the applications process. There is no better way to determine machine performance than with the actual process material. It is invaluable for customer application efforts. Computer modeling cannot account for particle variations like shape, density, and slurry viscosity. Every sample is different. Depending on the origin of the sample and communition method, some particles may be needle like, while others more spherical still others thin and flat.

These variations cause the materials to screen differently. For these reasons, the most reliable way to determine process performance is by testing in Derrick’s Testing Laboratory. Derrick applies state-of-the-art equipment to perform tests. Derrick encourages customer involvement in the tests; as your knowledge and experience ensures your companies objectives are achieved.