Coal mining activities resulted in solid and liquid wastes might affecting environmental quality. One of mining waste properties related to reducing the environmental quality is acidity properties. The acidity of mining liquid wastes was usually decreased by either actively or passively netralization processes. However, the netralization process might be not effective due to any pollutant including suspended solid waste present in liquid wastes. Suspended solid waste might contain organic and inorganic materials subsequently reducing acid netralizing capacity. The present study was conducted to evaluate sequence of coagulation and netralization processes on reducing acidity properties of mining liquid wastes including pH, Fe and Mn. Evaluation was carried out in situ at processing ponds in one of coal mining companies in Central Kalimantan. Results showed that acid netralizing capacity of the processing pond was hampered by any suspended solid present in liquid waste. This implies that the sequence of coagulation and netralization processes determines success of reducing acidity properties of coal mining liquid waste. However this depends on initial condition of the liquid waste.