A Day at Oakamoor Quarry with WBB Minerals
By Laurence Gale MSc
WBB Minerals is a multi-national provider of advanced industrial minerals to the world's ceramics, glass, sports surface, and foundry and construction industries. The company has operations in nine countries across Europe and over 6,000 customers globally, making it one of the world's largest suppliers of industrial minerals.
Each year the company identifies, extracts and processes around 11 million tonnes of material from extensive reserves of silica sands, plastic clays, kaolins, red-firing clays and dolomite. Backed by the strengths and resources of their parent company, SCR Sibelco, WBB Minerals believes it is better placed than anyone to meet the immediate and future raw material needs of the sports turf industry through its Rufford and Pro-Sport brands.
With ever increasing performance criteria for sports pitches, both natural and artificial, it is essential that the products used in their construction meet stringent testing standards and conform to specified criteria for their intended use.
WBB Minerals have heavily invested in a research and development (R&D) programme in the UK, which includes a number of laboratories that can test, measure and monitor all the products they produce from their quarries both in the UK and abroad. The company operate from 10 manufacturing sites across the UK.
From across the UK a range of sand grades are produced from medium-coarse to medium-fine which are used in top dressings, rootzones and bunker sands. A range of very fine sand grades are also produced specifically for the equestrian market. Oakamoor quarry produces sand for glass production, some construction sands, golf bunker sand, medium-coarse rootzone sand and sand for divot mix. Other speciality products are also manufactured here such as ground cristobalite and quartz, which can be used in investment casting powders, rooftiles, resin sinktops, plastics and polymers.
Oakamoor (Moneystone) Quarry
My guides for the tour were Production Manager, Rob Vickers, and Mick Higgins, Sports & Leisure Technical Manager (UK). Rob is responsible for all the quarrying processes at the quarry, managing over 40 staff who operate and maintain all the plant involved in the production, transport and refining of the sands.
The first task is to extract the sandstone material from site. This is done by ripping the rock using a large dozer, large dump trucks are used to carry up to 50 tonnes of material in one load to the refinery buildings. This is where the rock is crushed, screened, washed and graded. This sand can then be stockpiled for despatch or further processed using driers, kilns, mills, etc.
A large proportion of sand produced is used in the manufacture of glass bottles. These sands need to have a high silica content with very low impurities otherwise the glass produced will be tinted. To achieve this exceptional purity the sand is leached with hot acid then washed and stockpiled.
For some industries even this sand is not white enough so here the sand is fed through high temperature kilns (over 1500 oC) this modifies the silica and turns it into cristobalite, this product is pure white.There is also the capability of milling either silica sand or cristobalite which produces very fine powders which are used in a wide variety of industrial applications and shipped worldwide. Once the sands have been processed into their respective grades, quality control tests are carried out to determine their particle size distribution (sieve analysis). Chemical analysis is also carried out
Oakamoor quarry is also the location of WBB Minerals Group Central Laboratory (GCL). The laboratories here not only analyse products from around the world but can replicate most quarry refining process/techniques available. Using a scaled down version of quarry plant and equipment sand can be processed using spiral separators, screens, attrition scrubbers, hindered settling tanks and other washing equipment.
An important quality control procedure for sands used in the glass industry is to test for the amount of iron in the sand. Higher amounts of iron can tint the colour of clear glass. X-ray Fluorescence (XRF) is used to determine the amounts of silica, iron, alumina and potash.
In the labs I met Sasha McCann, who is their Sports Surface Technologist. Sasha is responsible for managing all the testing programmes of sports and leisure related products manufactured by WBB Minerals. Sand and organic amended products are tested for particle size distribution (PSD), organic matter content, pH, saturated hydraulic conductivity (drainage), water retention, bulk density, particle density, air filled and water filled porosity and moisture content.
Bunker sands are formulated and tested to meet the needs and requirements of the golf industry. WBB Minerals leading bunker sand grade, Moneystone Bunker sand, is produced at Oakamoor and is very popular with greenkeepers throughout the UK.
The selection of bunker sands are important, particularly if used in bunkers close to USGA constructed greens. When a shot is played from the bunkers the sand can often be flicked onto the playing surface; if the sand content from the bunkers is not compatible to that used in the green it could cause future drainage problems.
In recent years the company has been working closely with WRAP (Waste and Resources Action Programme), researching and trialling recycled products. Recycled glass is now becoming more popular especially with Local Authorities who are keen to implement environmental strategies. Glass has been used in golf bunkers, either on its own or blended with silica sand. Some courses have found it can offer good results, however, it is still marginally more expensive compared to sand. Recycled glass can also be used in a rootzone to replace sand and further research is being carried out.
WBB Minerals sports surface laboratory is one of only three in the UK which participates in the USGA Proficiency Testing Programme, the others being STRI and ETL. This utilises the American Society for Testing and Materials (ASTM) procedures. WBB Minerals have been taking part in the USGA PT programme for some ten years now and have refined both their equipment and expertise in this important area of testing.
Sasha manages two laboratories, one of which undertakes all the tests relating to sports materials, ensuring that all the products measure up to the standards set by the industry. The criteria and quality now expected by architects and designers is very exacting, with precise tolerances to be met.
In recent years Mick has been working with WRAP and other environmental agencies to develop products using green compost amendments which can be utilised by WBB Minerals in sports and leisure rootzones and top dressings. Look out for new WBB products which are to be launched later this year.
The company is constantly seeking to develop and modify products to meet the needs of the industry, some example have been the use of WBB Minerals Devon Lignite, Zeolite, and modified sands. The growing fashion for the new 3G artificial pitches has led to the production of a new all in one sand/rubber product, which negates the problems associated with the of migration between the two materials. Each sand particle is coated with rubber and comes in a choice of size and colour.
Keeping up with the pace of these changes and, more importantly, supplying quality, consistent products is Mick's main aim. Our industry has moved at a frightening speed in promoting quality playing surfaces. Modern technology continues to challenge us all. Without the ability to test materials efficiently and rigorously we would not be able to meet these demands.
With the strength of its Rufford and Pro Sport brands, and the fact that they have a worldwide back up in resources and materials, WBB Minerals is in a good position to deliver quality products for the sports turf industry.
With the 2012 Olympics around the corner the demand for quality materials will become even greater. If we want to achieve gold medal performances we will need to produce gold medal surfaces. The philosophy is simple: WBB Minerals aim is to consistently provide premium-quality products backed by the highest standards of technical support and customer service. To achieve this they have placed research and development at the very heart of our business. That's why their product range is constantly expanding and always embraces the very latest mineralogical technology.