Maxon equipment applications include; processing tailings from mining operation; paste treatment and backfill applications for underground hard rock mines; remediation of existing and closed mine tailing ponds; and tailing processing for coal fired power plants. Equipment includes single and twin shaft mixers, remixers and agitators for processing and placement of thickened tailings or paste. Maxon Maxcretes and Agimaxs are used extensively for accepting tailing slurry, mixing or blending with cement or flyash to create a paste or slurry, and continuously feeding to placing devices including concrete pumps, conveyors or directly to stock piles or landfill.
Mine Tailing Remediation
Most mining operations generate tailings when separating the valuable minerals from the excavated ore body. Historically, those tailings were discharged into ponds, impoundments, mine dumps, clum dumps, slime tailings, leach residue, tailings dams, or slickens. Here the tailings tend to leach water that will carry heavy metals or other contaminants. In extreme cases, the tailings ponds have failed causing environmental damage, including contamination of ground water or local tributaries. Mining operators and sub contractors are now taking steps to remediate tailings from ongoing operations to reduce or prevent future environmental destruction. Maxon supplies a complete solution for converting tailings to a paste, including mixing, transporting and placing mine tailings.
Coal Power Plant
Coal–fired power plants currently fuel 37% of global electricity and create a number of waste streams including, overflow from floatation tanks to separate fine coal and the separation of unburned carbon from the bottom ash. Treatment solutions include dewatering of the tailings with belt presses and using paste thickener technology (addition of cement) and processing of underflow tailings as part of the floatation process. Maxon offers complete engineered equipment solutions including mixers/pugmills (Maxon Maxcrete) and concrete pumps to process and place the tailings. Dewatered tailings are often achieved with belt presses, and the remaining tailings can then be thickened and pumped by pipeline to the disposal area.
Maxon custom engineers and manufactures equipment to meet specific customer requirements for in-plant applications. Projects include mineral processing operations for mines, and treatment of waste streams generated from power plants. Equipment is engineered to meet site requirements including; building envelopes; tailings flow rates; material consistencies; introduction of thickeners like cement or flyash; mixing, blending or agitating material; and discharge to pumps, conveyors or trucks. The image above is a 26 yd3 (20m3) capacity Maxon Maxcrete (blue mixer) installed at the Pretium Gold Mine processing plant in British Columbia, Canada.
For remediation of existing tailings ponds, Maxon offers a line of mobile or portable equipment. Waste material from tailings ponds are excavated by crane/bucket or excavator and fed directly to an open top Maxon Maxcrete, then mixed with a solidification agent (cement, fly ash, kiln dust, etc). On the above project, the contractor utilized a 10 yd3 (7.6m3) Maxcrete to blend 5% cement with the tailings, simultaneously mixing and discharging to a concrete boom pump. The resulting paste was then pumped into abandoned mine cavities to be used as backfill material.