Abstract: This invention presents a versatile and continuous drying technology that utilizes controlled heat combined with forced air supply for drying a feedstock. The dryer virtually divided top-down into different zones, each having definite heated air distribution rate to secure desired condition for drying of the feedstock. The heat source of the dryer is waste heat, either provided by the feedstock itself through exothermic heat generated by the feedstock or reclaimed waste heat or solar heat. The discharge system of the dryer is a fail-safe discharge system, which ensures equal residence time for the feedstock through all the zones.

Abstract: The invention relates to a method for drying slurry-like materials, in particular sludge from wastewater treatment plants, including two drying stages, namely: a first indirect drying stage (2), supplied with hot fluid, which receives sludge having an entry dryness Se, and outputs sludge having an intermediate dryness Si and water steam, which is channelled towards a condenser (8) in which a heating fluid, in particular water, is reheated and, in turn, heats a heating gas for a second drying stage (6); and a step (5) of forming strings of sludge at the exit from the first stage; the second stage (6) of drying the strings of sludge using gas at least partially heated by the heat extracted from the condenser, said second stage outputting a slurry having a final dryness Sf; the intermediate dryness Si is controlled according to the measured entry dryness Se and the desired exit dryness Sf, for minimum consumption of the total energy used for drying, the flow rate, pressure and/or temperature of the hot fluid (3)

Abstract: The present invention provides methods and systems for reducing moisture in mineral slurries, particularly mineral slurries containing minerals of small particle diameter, using a granular drying material. The invention also relates to novel mineral products and intermediates useful in connection with the process. The method and system reduced moisture by contacting the mineral slurry with the granular drying material. The granular drying material is selected to be readily separated from the dried minerals using a size separation technique such as a sieve screen. The granular drying material is the regenerated, preferably using a process involving heat exchange and cross-flow air. The granular drying material is preferably capable of regeneration and recycling in a continuous process with minimal attrition.

Abstract: A desiccating device and method providing variable drying conditions allowing the desiccated material to substantially maintain its natural characteristics upon rehydration as well as have a low microbial content. The method provides a process of subjecting the material to ultrasound and flowing hot air or gas for a defined period of time. The ultrasonic frequency, temperature, air flow and time of exposure can be varied to produce the most efficient drying conditions depending on the material to be dried. The apparatus has plurality of drying chambers with forced heated air or gas input and output ducts and ultrasonic emitter. The material passes through each chamber at a pre-determined rate on a perforated conveyor belt in one embodiment of the invention. Optionally, the material may be placed on a drying bed or substrate comprising a number of spheres.

Abstract: The present invention provides a method and system for drying mineral slurry concentrate and high moisture content minerals using activated alumina. The method and system dries the mineral slurry concentrate by combining the slurry with the activated alumina. While in combination, the mixture is agitated to maximize surface contact between the activated alumina and the slurry. As the mineral slurry concentrate contacts the activated alumina, the surfactant moisture on the mineral elements is then absorbed by the activated alumina. The activated alumina allow for the water molecules to be adsorbed by the activate alumina, thus being removed from the slurry elements. After a period of agitation, the method and system thereby separates the activated alumina from the mineral slurry concentrate.

Abstract: A method of dewatering fine particulate materials is disclosed. In this method, an aqueous slurry of fine particles is treated with appropriate hydrophobizing reagents so that the particulate material becomes moderately hydrophobic. A lipid of vegetable or animal origin is then added to the slurry in solutions of light hydrocarbon oils and short-chain alcohols, so that the hydrophobic lipid molecules adsorb on the moderately hydrophobic surface and, thereby, greatly enhance its hydrophobicity. By virtue of the enhanced hydrophobicty, the water molecules adhering to the surface are destabilized and more readily removed during the process of mechanical dewatering. The moisture reduction can be further improved using appropriate electrolytes in conjunction with the lipids, spraying surface tension lowering reagents onto the filter cake, subjecting the cake to a suitable vibratory means, and using combinations thereof.

Abstract: The invention is directed to a process and apparatus for drying a slurry, particularly a sludge, such as sewage sludge, in which a sludge mixture of recycled dried sludge and wet sludge is fed to a drier. The quantity of wet sludge or recycled dried sludge supplied to the drier is controlled based upon drier inlet temperature. In this way, the evaporation rate of the drier is kept substantially constant.

Abstract: A process for treating paint sludge in which previously cured paint sludge powder is used as a diluent and mixed with wet paint sludge. The paint powder/sludge mixture is agitated and heated to cure the paint sludge. Processing can occur either continuously or in batch mode, and can be accomplished using a mixer charged with heated gases, or a heated mixer.