Investigation of mineral deformation and dissolution problems under various temperature conditions

To understand the effects of temperature on the pressure dissolution of mineral, we conducted some experiments using monocrystalline quartz samples. The first of these was a flow thorough experiment to investigate temperature effects for dissolution mechanism. The samples were stressed mechanically by pressing one sample against the other. The flow through experiments was conducted at two different temperatures (35 and 70 °C) at the same pH (pH 11.7) level. The value of the applied stress was 7.32 and 25.27 MPa. During each of these dissolution tests, the solution was sampled regularly and analyzed by an Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) technique to measure Siconcentration. With the measured Si-concentration, a dissolution rate constant was computed for variety of stress and temperature conditions. It is therefore shown that the rate constant is proportional to the temperature, as expected and as indicated in the literature. It should be noted that the rate constant for the highly stressed case (25.50 MPa) and highly temperature case were considerably greater than for the mildly stressed cases and lower temperature cases. Also, island-channel patterns characterized by micro-cracks a few nanometers in length were seen on the dissolved parts of the samples. The findings and the measured data in this research may be useful for the future development of theoretical models for pressure dissolution and its validation.