ZLD Mining: Wastewater and sludge
Problem
Mining can have a negative effect on the quantity and quality of groundwater and surface water in mining areas (Bebbington and Williams 2008; Vidic et al. 2013), threatening the sustainability of water resources (Yang et al. 2013) and public health of local residents (Li et al. 2016; Wu and Sun 2016). Ecological degradation and health problems due to mine waste discharges have been reported around the world (Esteller et al. 2015; Njinga and Tshivhase 2017; Wright et al. 2017), attracting the attention of both policy makers and researchers. (Peiyue Li. 2020).
Solution
Our plants with IKERA RD8 technology are designed for wastewater, sludge, and leachate from small to medium-scale mining, managing to recover up to 99.8% of the water, leaving the solid part in a totally dry format which offers possibilities for revalorisation.
It recovers oil as well as some VOCs from the original residue.
Process
Thermal energy is the main source of energy used, which can be generated from non-renewable sources and renewable energy such as CSP, MINI-CSP, FVT, geothermal, biomass, waste heat or a combination of the above mentioned.
The sludge, concentrated and leached, is continuously pumped into a tank in which we ensure the homogenisation of the waste. The waste then continues through the IKERA RD8 physical reactor in which only H2o evaporates and condensates.
The now condensed pure water can be reintroduced to the industry or discharged into the network according to reuse or discharge parameters.
The solid part, adjusted to a humidity as low as 0.2%, is taken out of the reactor and prepared for revaluation or transfer.
In case of having different solid elements, all of them are in the dry solid mix. There is no selective separation inside the reactor at this point in the process.
Oils, if any, are recovered in a different stream as are some VOCs.
Situation
We have conducted over one hundred viability studies on wastewater and sludges, successfully recovering the water and the solid part.
Each sludge represents a challenge and while there are thousands of them we are comfortable to report no failure during our viability studies.
Further separation of the solid parts needs to be researched case by case, depending on the elements involved.
We are looking for industrial partners or venture capital for industrial scaling up.
Readings of interest
Agua, cianuro y minería del oro: 30 años de accidentes
https://www.iagua.es/blogs/plataforma-salvemos-cabana/agua-cianuro-y-mineria-del-oro-30-anos-de-accidentes
Universidad de Huelva
https://www.aguasresiduales.info/revista/noticias/rios-rojos-el-problema-ambiental-de-las-aguas-acid-g4z9e
Innovyze
https://www.innovyze.com/en-us/blog/top-6-ww-treatment-problems-facing-the-metals-and-mining-industry
The verge
the wastewater disaster in florida is a symptom of how we grow our food
https://www.theverge.com/22371931/fertilizer-toxic-legacy-florida-wastewater-disaster-piney-point-phosphate
Wikipedia
2015 Gold King Mine waste water spill
https://en.wikipedia.org/wiki/2015_Gold_King_Mine_waste_water_spill