Mines have particular logistical, safety and environmental requirements that need to be considered when designing concrete and this is in addition to meeting demanding performance specifications. Among the global leaders in concrete admixtures, CHRYSO understands this and has an extensive product offering to meet varying operating conditions.
In addition to experience in designing shaft lining concrete, CHRYSO has the expertise to formulate high-flow, highly accelerated concrete that can be transported through slick lines. This expertise also encompasses providing solutions for shotcreting, thin skin liners, tailings grout support and backfill.
Driven by the advances in admixture technology, the use of sprayed concrete as a temporary and permanent support element on mines has increased significantly in recent decades. CHRYSO admixtures control the workability of concrete and create longer open times. They also lower cement-to-water ratios, improve early or late strength development and reduce rebound.
Used extensively on copper, gold, platinum and diamond mines, the CHRYSO® Jet range of accelerators ensures early hydration of concrete. It also allows the concrete to be formulated to suit the size of the shotcrete machine, as well as shotcrete thickness. To reduce rebound and improve early strength in dry shotcrete, CHRYSO® HPB Powder assists with bonding in wet conditions.
CHRYSO’s market-leading expertise has made it the first supplier to develop the use of tailings shotcrete and concrete to help alleviate mines’ logistical issues. Now, the bulk of the material can be pumped over long distances and stored before being sprayed.
A significant portion of CHRYSO’s shotcrete fibre range is made from polypropylene and is specially coated to increase bond strength. Capable of replacing mesh reinforcement used for reduction of shrinkage cracking, these are low-dose fibres that do not clog pumps. Where material needs to be pumped over a long distance from the mixing plant to the point of application, CHRYSO® Fluid Optima T4 is a powerful superplasticiser with a long open time.
When it comes to thin skin liners (TSLs), CHRYSO has pioneered two dustless products for the mining industry. Its patented single part and liquid polymer are safer and healthier to use than traditional TSLs.
There are several CHRYSO solutions to improve the stability of tailings grout. CHRYSO® Fluid Optima 206, for instance, is a superplasticiser that reduces shrinkage in grout packs. This allows the packs to better support the hanging wall.
The CHRYSO® Eco Dust range of dust suppressants includes a surface primer, as well as a surface sealer that is an emulsified dust lubrication system. It also has a fine particle size poly-adhesive for dust binding and an emulsified surface lubricant that coalesces particles to form a dust suppressing film.
At the forefront of using admixtures in backfill, CHRYSO products increase the density of pumped grout while reducing costs through less cement content. These admixtures can vary the flow characteristics of cementitious backfill and grouts, using less energy while achieving better settlement rates and compaction of the final backfill.
Part of CHRYSO Southern Africa since 2010, a.b.e.® Construction Chemicals has a unique range of chemical-resistant coatings and waterproofing solutions for mines’ processing plants. This includes specialised concrete repair systems and polyurea-based protective coatings for concrete and steel.