PRECIPITATION OF COLLOID SILICA FROM HYDROTHERMAL SEPARATE BY COAGULANTS ADDITION ( KAMCHATKA , RUSSIA )
We have carried out the experiments on coagulation and precipitation of silica from the separate of Verkhne-Mutnovsky geothermal electric power plant (Mutnovskoe hydrothermal field). Silica precipitation from the water solution was conducted in two ways: by adding slaked lime CaO and by electrocoagulation treatment on aluminium electrodes. Silica precipitation with addition of slaked lime was carried out under laboratory conditions at the temperature of 20 and 96 °C. Сolloid and monomeric silica concentrations, solution pH, flakes sizes and physical-chemical properties of material precipitated with different quantities of added lime were determined. We also carried out series of experiments on solution treatment of mixed type: addition lime with freshly precipitated flakes, and addition lime with sea water. In the experiments on electric coagulation, current intensity and distance between electrodes were changed. Dependence of silica concentration on treatment duration was studied. Quantities of electric energy and anode aluminium consumed for reducing of silica concentration to a certain level were obtained. The results of our experiments can be used for developing of technological scheme of silica precipitation and utilization optimal for Verkhne-Mutnovsky geothermal electric power plant.
Towards the efficient utilization of geothermal resources
Abstract Separated geothermal water from production wells at Wairakei, Ohaaki, Kawerau, Ngawha and other less developed fields in New Zealand, contains potentially valuable chemical constituents. In particular, the extraction of precipitated amorphous silica is discussed in terms of its strategic and beneficial value to expanded energy generation in geothermal development, removal of environmentally sensitive constituents and as a marketable commodity in its own right. The prospect of recovering other minerals thereby realising the full potential of geothermal resources is considered. Expectations regarding high temperature reinjection could be reviewed in consideration of alternative opportunities which have been advanced in recent years.
Application of Automatic Tracking Correlation Filtering in Motored Spindle Dynamic Balancing
According to the information characteristics of the dynamic imbalance signal and the definition of correlation function,the principles and algorithm of relevant filter with automatic tracking is given.In labview development system,based on the principles of relevant filter with automatic tracking,the graphics programming of extracting the dynamic imbalance signal is developed.With this programming,the vibration signal including different frequency harmonic signals and noise is processed by simulation and on-site experiment.The results show that: through relevant filter with automatic tracking,the dynamic imbalance signal under different rotating speed can be extracted accurately,and it can meet the requirement of motored spindle dynamic balancing measurement.