Salamanca, JM, Rodríguez, HE & Moreno, MM 2017, 'Design and construction of a prototype for acidity level control in coal mining liquid effluents', in M Hudyma & Y Potvin (eds), UMT 2017: Proceedings of the First International Conference on Underground Mining Technology, Australian Centre for Geomechanics, Perth, pp. 663-675, https://doi.org/10.36487/ACG_rep/1710_56_Salamanca
(https://papers.acg.uwa.edu.au/p/1710_56_Salamanca/)
Abstract: It is a challenge of modern industry to develop processes that do not pollute the environment, most importantly water. The mining industry is no exception, and in turn must minimise environmental impact on water sources in or around areas of exploitation (Garner et al. 2012). The management of drainage in the depth of the mine is a problem due to high costs, and it is important to understand that the cost of the consumption of electric energy rises according to the size of the mine and the quantity of drainage.
This paper describes the design and implementation of a prototype to neutralise the acid water of mining in the didactic coal mine located in Morcá (Sogamoso, Colombia), which belongs to the Centro Nacional Minero (National Mining Centre), Servicio Nacional de Aprendizaje (SENA, Sogamoso, Colombia). 
The neutralisation of these acidic waters aims to minimise the environmental impact produced by these liquids, when they are discharged into nearby water sources. The neutralisation method is ‘additives base’, which comprises mixing a basic agent; in this case, caustic soda (NaOH) at a concentration of 1 Normal (1N) was used. In order to carry out this process, the system model is estimated and proportional plus integral (PI), algebraic, fuzzy logic and sliding mode controllers were applied to the prototype. A comparison of the performances of the different controllers showing the response time overshoot, steady state error and magnitude of the control signals are shown and analysed.

Keywords: pH, acid water, caustic soda