Acorn has two main options for the disposal/recovery of this material, both of which vary in terms of economics and environmental sustainability. We cater for long term disposal contracts as well as once off projects. Please contact us for a quotation or additional information.
The two options which are available are:
Quarry Remediation Project
Recovery of Alum in Cement Kiln
RECOVERY OF ALUM SLUDGE IN CEMENT KILN
In the cement manufacturing process the primary ingredients are limestone, shale and overburden which are extracted from quarries adjacent to the plant and processed through primary and secondary crushers. An enclosed preblending facility caters for the blending and storage of a raw mix. As well as the primary ingredients, other materials added include Bauxite and sulphurous compounds. These add essential additives to the mix. Bauxite contains aluminium which helps the process in producing a good cement product.
Alum sludge contains a level of aluminium deemed suitable for use in a cement kiln. The only issues with utilising the material is that usually only stone and powdery product is added to the system. In the circumstance where alum sludge is added, modifications are necessary in the feed systems which allow this to happen. Significant investment was made to facilitate the addition of sludge at reasonably low solids percentage. Though the licence stipulates 24% Dry solids are allowed, this can be achieved by blending the alum product with other materials prior to it being processed. This is achieved in the specialised blending area.
The option for the alum is considered an R code, deeming the option to be Recovery and would be considered a sustainable solution to a waste problem.
QUARRY REMEDIATION OPTION
This option, being a disused quarry is to remediate and rehabilitate the site to its former environment. This is achieved by obtaining a landfill licence which allows the utilisation of construction waste, stone, soils, sand and other such materials and that fulfil strict chemical and physical criteria.
The materials can be stockpiled on site and/ or immediately used as fill. Certain sections of the site are isolated and monitored for groundwater contamination while they are being filled with material. Once the cells are filled, the sites are vegetated and left as agricultural land.
The option again has the backing of the EPA and is a viable and economic option for WTS.
The method of managing the sludge is, under the terms of the EPA landfill licence, considered to be Deposition of inorganic materials and recovery and reclamation of other inorganic materials as well as activities relating to storage and metals recovery.
As apposed to conventional landfill this option is sustainable as the objective of the deposition into this facility is not merely to dispose of the sludge as waste but to utilise it for the purpose of restoring an old quarry.
