Waste and raw materials
OUR VISION: A responsible business which uses both raw materials and waste beneficially and has a minimal impact on the environment.
Although our levels of controlled waste are relatively minor in comparison to the volume of materials we produce, we aim to minimise the amount generated.
During our extraction and processing we use as much material as possible in the production process. Where surplus overburden or quarry production waste is generated, it is generally back-filled as part of landscaping and restoration activities.
In addition, a number of projects are under way aimed at increasing our use of recycled materials, including crushed concrete, construction and demolition waste, spent rail ballast and asphalt planings. These materials replace primary aggregates in added-value products such as ready-mixed concrete and asphalt.
A key example is in the production of the cement replacement Regen (ground granulated blast furnace slag), a by-product from the manufacture of iron. This is used in a third of all our ready-mixed concrete, reducing embodied CO2 and providing a number of other benefits. It can replace over 50 per cent of the normal Portland cement content.
Over half of our asphalt plants can use recycled asphalt planings (RAP) in base course mixes at rates of up to 25 per cent. Our subsidiary Midland Quarry Products has a particularly good track record in the use of RAP and we are introducing techniques developed at MQP throughout the business to improve overall performance.
Waste to landfill
We reduced waste to landfill by nearly 3,000 tonnes or 29 per cent in 2014. The majority of our sites are included within a single contract with Biffa, a national waste disposal company, which enables us to control the process more effectively and provide further data on the quality and types of waste being produced. Dry mixed waste bins have been provided at all our sites to collect recyclables including plastic, paper and cardboard. The waste is taken to a network of depots for recycling with any residue used for energy recovery.
The use of cement bypass dust as an agricultural land improver has gradually increased over the last two to three years due to its high lime and potassium content.
Waste as fuel
We continue to invest in new facilities at our three cement works to enable greater use of alternative fuels. These include profuel – a solid kiln fuel manufactured from paper, plastic and fibrous wastes that are either uneconomic or impossible to recycle, and solid recovered fuel (SRF), which is made from domestic waste and biomass. Overall use of waste as a fuel in our cement kilns continues to rise, although the use of biomass has fallen due to difficulty in sourcing material of suitable quality.
A key objective is to increase the use of alternative fuels for cement and to draw up a wider strategy that will maximise opportunities across all divisions.
In cement the target is to substitute more than 65 per cent of fossil fuels with sustainable alternatives in the three plants at Ketton, Padeswood and Ribblesdale. At present the average is around 58 per cent.
Hanson’s asphalt division has kicked off a multi-million pound investment programme to reduce energy consumption, increase the use of recycled products and improve the reliability of its plants.