a 'refractory' gold ore is an ore that has ultra fine gold particles disseminated throughout its gold occluded minerals. these ores are naturally resistant to recovery by standard cyanidation and carbon adsorption processes. these refractory ores require pre-treatment in order for cyanidation to be effective in recovery of the gold. a refractory ore generally contains sulfide minerals, organic carbon, or both.
agitation is further assisted by the use of tank baffles to increase the efficiency of agitation and prevent centrifuging of slurries in circular tanks. extraction efficiency factors. aside from chemical requirements several key factors influence extraction efficiency: retention time - refers to the time spent in the leaching system by the solids. this is calculated as the total volumetric capacity of the leach tank/s divided by the volumetric throughput of the solid/liquid slurry.
dbacks of leaching include its lower efficiency and the often significant quantities of waste effluent and tailings produced, which are usually either highly acidic or alkali as well as toxic e.g. red mud . there are four types of leaching: cyanide leaching e.g. gold ore ammonia leaching e.g. crushed ore alkali leaching e.g. bauxite ore
rp-1 alternately, rocket propellant-1 or refined petroleum-1 is a highly refined form of kerosene outwardly similar to jet fuel, used as rocket fuel.rp-1 has a lower specific impulse than liquid hydrogen lh 2 , but is cheaper, stable at room temperature, far less of an explosion hazard, and far denser.rp-1 is significantly more powerful than lh 2 by volume.
a photobioreactor pbr is a bioreactor which incorporates some type of light source that may be natural sunlight or artificial illumination . virtually any translucent container could be called a pbr, however the term is more commonly used to define a closed system, as opposed to an open storage tank or pond.photobioreactors are used to grow small phototrophic organisms such as cyanobacteria .
the water is heated and then routed into a reduced-pressure flash evaporation 'stage' where some of the water flashes into steam. this steam is subsequently condensed into salt-free water. the residual salty liquid from that first stage is introduced into a second flash evaporation stage at a pressure lower than the first stage pressure. more .