Abstract: In gold and/or silver cyanide leaching-adsorption processes employing solid adsorbents such as activated charcoal, the overall efficiency in the recovery of gold and/or silver from ores or the like is greatly increased by contacting the cyanide slurry containing the gold and/or silver, with oxygen gas instead of normal air. A generally pure oxygen gas can be bubbled into a vessel containing the slurry, and a cover (e.g. a floating cover) may be provided on the vessel to reduce the oxygen transfer out of the solution and to facilitate pressurization of the system with an oxygen atmosphere. The procedures of the invention are applicable to carbon-in-pulp (CIP), and carbon-in-leach (CIL) processes and related processes using resins. Deaeration of the ore slurry can be practiced prior to the introduction of the oxygen.

Abstract: A multi-stage flash evaporator is constructed so that the evaporator elements are dimpled plates mounted so that they extend horizontally. One, two, or more sets of plates may be mounted in each evaporator stage, the sets stacked upon one another in a tier arrangement. Each stage may be formed by a circular cross-section vessel, with I-beams--or like supports--extending horizontally at about the horizontal diameter of the vessel, and supporting the dimpled plates on them. A condensate collection trough is mounted below the dimpled plates and at the I-beams, the I-beams having openings in them through which condensate collected by the trough passes from one end of the vessel to the other. The hot liquid --such as sea water to be desalinated--to be evaporated is passed into a bottom chamber of each stage vessel, with vapor flowing upwardly through demistors and channels, into contact with the dimpled plates, and the condensate falling as a thin film down the plates and collecting in the condensate trough.

Abstract: The waste heat from a steam turbine is condensed and used to desalinate sea water at the same time. The waste steam from a turbine is fed to a condenser through which cold sea water passes. As the cold sea water condenses the waste steam, it is warmed. It is then introduced into a first chamber which includes a number of spray heads disposed over fill (packing) that acts as an evaporator. Any water not evaporated is collected in a sump at the bottom of the first chamber, and the evaporated vapor is passed upwardly under the influence of a fan and ultimately to a second chamber. The second chamber may either be stacked above the first chamber, or in side-by-side relationship with it. A condenser, such as a number of dimpled metal plates, or plastic membranes defining a closed loop, or another set of spray heads and fill, are provided in the second chamber. Air typically recirculates from the bottom of the second chamber back into the first chamber.

Abstract: The number 2 flash tank of a black liquor energy recovery system associated with a continuous pulp digester is eliminated, and other advantages are obtained. After flashing in the number 1 flash tank, concentrated black liquor passes to a multiple effect evaporator system as the heating fluid supplied to the last effect. The heated black liquor passes in heat exchange relationship with excess make-up liquor from the high pressure feeder circulation system and/or with portions of the extracted black liquor that have had more of their content removed, the heated black liquor effecting evaporation of the excess make-up liquor and/or portions of the black liquor. Steam from the steam relief of the steaming vessel may be used as a secondary heating fluid source for the first effect.

Abstract: In carbon-in-pulp (CIP) and carbon-in-leach (CIL) processes, especially those utilizing pure oxygen instead of normal air to increase the overall efficiency of the cyanide leaching-adsorption process in the recovery of gold and/or silver from ores, the screen within each tank which surrounds the slurry outlet is kept clean. The cleaning action is accomplished by linearly reciprocating the screen first slowly in one direction, and then quickly in another (to cause back flushing); or by rotating a cleaning rotor on the inside of a cylindrical screen. The cleaning rotor may be connected to the same shaft as an agitator disposed above a draft tube within the tank. The screen surface is tapered in its direction of movement, and during movement has a tendency to transport and concentrate the carbon (charcoal) particles at the far end of the slow stroke, and the concentrated particles can be withdrawn and recirculated to other tanks in the system.

Abstract: In carbon-in-pulp (CIP) and carbon-in-leach (CIL) processes, especially those utilizing pure oxygen instead of normal air to increase the overall efficiency of the cyanide leaching-adsorption process in the recovery of gold and/or silver from ores, the screen within each tank which surrounds the slurry outlet is kept clean. The cleaning action is accomplished by linearly reciprocating the screen first slowly in one direction, and then quickly in another (to cause back flushing); or by rotating a cleaning rotor on the inside of a cylindrical screen. The cleaning rotor may be connected to the same shaft as an agitator disposed above a draft tube within the tank. The screen surface is tapered in its direction of movement, and during movement has a tendency to transport and concentrate the carbon (charcoal) particles at the far end of the slow stroke, and the concentrated particles can be withdrawn and recirculated to other tanks in the system.

Abstract: The number 2 flash tank of a black liquor energy recovery system associated with a continuous pulp digester is eliminated, and other advantages are obtained. After flashing in the number 1 flash tank, concentrated black liquor passes to a multiple effect evaporator system as the heating fluid supplied to the last effect. The heated black liquor passes in heat exchange relationship with excess make-up liquor from the high pressure feeder circulation system and/or with portions of the extracted black liquor that have had more of their heat content removed, the heated black liquor effecting evaporation of the excess make-up liquor and/or portions of the black liquor. Steam from the steam relief of the steaming vessel may be used as a secondary heating fluid source for the first effect.

Abstract: Wood chips, or like comminuted cellulosic fibrous material, are treated in a vertical presteaming vessel in the production of paper pulp. The vessel does not employ a vibrating discharge structure as is conventional, but rather utilizes as a discharge structure a plurality of rotating arms having depending blades, mounted at the bottom of the vessel, which force the wood chips toward a discharge opening in the vessel bottom. The steam is introduced into the vessel through a vertical tube concentric with the vessel, and surrounding a rotatable shaft which is connected to the arms of the discharge device. A truncated cone is provided at the bottom of the steam tube, making a slip connection with the tube, and overlies the discharge opening. The cone has maximum horizontal dimensions greater than those of the outlet, to cause the chips to move radially outwardly into contact with the discharge element.

Abstract: In gold and/or silver cyanide leaching-adsorption processes employing solid adsorbents such as activated charcoal, the overall efficiency in the recovery of gold and/or silver from ores or the like is greatly increased by contacting the cyanide slurry containing the gold and/or silver, with oxygen gas instead of normal air. A generally pure oxygen gas can be bubbled into a vessel containing the slurry, and a cover (e.g. a floating cover) may be provided on the vessel to reduce the oxygen transfer out of the solution and to facilitate pressurization of the system with an oxygen atmosphere. The procedures of the invention are applicable to carbon-in-pulp (CIP), and carbon-in-leach (CIL) processes and related processes using resins. Deaeration of the ore slurry can be practiced prior to the introduction of the oxygen.

Abstract: An evaporator includes heating elements which are part of a thin skin providing the evaporator vessel wall, supporting the skin for internal and external pressure, and a top portion of the vessel. A liquor distributing plate is supported on the heating elements, with a liquor inlet donut-shaped conduit disposed above the liquor distributing plate. The heating elements are radially disposed within the vessel, and are supported at the bottom by a ring which engages the bottoms of the heating elements, and a vertical axis tube extending from the vessel bottom to the ring, the tube having a plurality of through-extending openings formed in it. The vapor outlet for the vessel is concentric with the heating elements and the liquor distributing perforated plate. Heating fluid (e.g. steam) is introduced into the interior volumes of the heating elements adjacent the tops thereof, and a vent is provided adjacent the bottoms.

Abstract: In gold and/or silver cyanide leaching-adsorption processes employing solid adsorbents such as activated charcoal, the overall efficiency in the recovery of gold and/or silver from ores or the like is greatly increased by contacting the cyanide slurry containing the gold and/or silver, with oxygen gas instead of normal air. A generally pure oxygen gas can be bubbled into a vessel containing the slurry, and a cover (e.g. a floating cover) may be provided on the vessel to reduce the oxygen transfer out of the solution and to facilitate pressurization of the system with an oxygen atmosphere. The procedures of the invention are applicable to carbon-in-pulp (CIP), and carbon-in-leach (CIL) processes and related processes using resins. Deaeration of the ore slurry can be practiced prior to the introduction of the oxygen.

Abstract: A method and system for the percolation leaching of gold and silver ores applies a cyanide leaching liquid to a pile of gold and silver ore. Heap leaching, vat leaching, or the like may specifically be practiced. The cyanide leaching liquid is applied to the pile by spraying, flooding, or via a foam of oxygen gas and cyanide liquid on top of the pile. Gold and silver are recovered from the pregnant liquor. The leach rate is increased and/or the recovery of gold and silver from the ore is increased by supplying to the pile a gas containing oxygen at a significantly higher percentage than in ambient air (e.g. pure oxygen gas). The oxygen gas may be supplied to the leaching liquid, and/or into the pile itself (as with a plurality of perforated pipes adjacent the bottom of the pile).

Abstract: A free flow evaporator of the falling film type has the heating elements disposed in a circular configuration so that each extends radially a distance less than the interior radius of the evaporator cylindrical vessel. Heating vapor is introduced concentrically into the top of the vessel and passes into the tops of the heating elements, and condensate is withdrawn from the bottoms of the heating elements in the vessel. Excess vapor passes through a vapor vent in the bottom of the vessel. The boiling liquid, such as black liquor from paper pulp processing, is introduced through a header above an annular channel with a perforated plate bottom, the perforated plate being disposed on top of the heating elements. The evaporated liquid vapor passes radially outwardly in the vessel, and then upwardly, and is discharged from the top of the vessel and passes to the top of another vessel (providing another effect), to provide heating vapor to the other vessel.

Abstract: An assembly and method provide for the simultaneous heating of process inlet water from a clean water source, and condensing of a condensable gas using the process inlet water and a closed loop of condensing water. A plurality of pairs of condenser plates are disposed in an annular array in a vertical cylindrical vessel. First and second liquid inlets are disposed at the top of the vessel separated by a radially extending fixed baffle, and first and second liquid outlets are disposed at the bottom of the vessel separated by a radially extending fixed baffle. A condensable gas passes through the interiors of the pairs of condensing plates. Movable top and bottom baffles are rotatable through arcs to change the number of condensing plates operatively communicating the first liquid inlet with respect to the second liquid inlet, the liquid flowing between the first liquid inlet and outlet being always segregated from the liquid flowing between the second liquid inlet and outlet.

Abstract: Metal is removed from particlized metal bearing refractory ores in an efficient manner utilizing pressure metallurgy with heat recovery. The particlized ore is mixed with a heated liquid, and preferably a flocculant and fibers, to form a slurry. The ore in the slurry is oxidized at superatmospheric pressure, and elevated temperatures (e.g. around 300.degree. F.). The oxidized ore is washed to remove acids, and like products of oxidation, and the washed ore is subsequently subjected to conventional leaching processes to effect an actual metal recovery. Heat recovery is practiced by utilizing spent wash water as part of the slurrying liquid, and using two or more liquid-interconnected vessels in effecting the oxidization.

Abstract: A method of treating biomass having fermentable material is provided utilizing acid hydrolysis in a countercurrent diffusion treatment structure. By practicing the invention acid usage is minimized, pentose concentration in the hydrolysate solution is maximized, and ethanol, butanol, butanediol, and the alcohols can be produced without the input of any external energy whatsoever into the production method. Biomass is particlized and slurried, and then is continuously subjected to acid hydrolysis at temperature, acid concentration, and residence time conditions sufficient to effect hydrolysis of the hemicellulose in the biomass to effect separation of pentose and hexose sugars into a hydrolysate having insufficient furfural to substantially inhibit fermentation microorganism growth, while not substantially hydrolyzing the cellulose in the biomass.

Abstract: Particlized mineral material, such as gold ore, silver ore, or coal, is subjected to a leaching process in a manner to maximize treatment effectiveness even when the particlized mineral material contains small fines. The material is slurried with a flocculating material and fibers, such as cellulosic fibers, fiberglass fibers, or ceramic fibers, and a liquid, and then is passed to the top of a leaching reactor. The slurry is continuously passed downwardly in the reactor while the leaching liquid, such as a cyanide solution, is passed counter-current to the slurry. Leaching liquid is removed from the top of the leaching reactor by a stilling well, and then passed through a carbon adsorber and reintroduced into the reactor. Leached slurry is passed to a continuous washing station, with spent wash liquid from the top of the washing station being utilized as a slurrying liquid for the particlized mineral material.

Abstract: An assembly and method provide for the simultaneous heating of process inlet water from a clean water source, and condensing of a condensable gas using the process inlet water and a closed loop of condensing water. A plurality of pairs of condenser plates are disposed in an annular array in a vertical cylindrical vessel. First and second liquid inlets are disposed at the top of the vessel separated by a radially extending fixed baffle, and first and second liquid outlets are disposed at the bottom of the vessel separated by a radially extending fixed baffle. A condensable gas passes through the interiors of the pairs of condensing plates. Movable top and bottom baffles are rotatable through arcs to change the number of condensing plates operatively communicating the first liquid inlet with respect to the second liquid inlet, the liquid flowing between the first liquid inlet and outlet being always segregated from the liquid flowing between the second liquid inlet and outlet.

Abstract: A method and apparatus are provided for the dehydration of low rank coal, such as lignite. The coal is formed into particles having a size of less than about 4 inches, is subjected to atmospheric steaming, and then preheating with steam at a pressure of about 20-100 psig. The particles are then entrained in liquid and fed to a high pressure feeder at which they are transferred to a high pressure circulation loop, at a pressure of between about 300-1500 psig. The particles and liquid are fed to a liquid/particles separator at the top of a vertical dehydrating vessel, and the particles at the top of the vessel are contacted by saturated steam. Condensed steam and particles flow downwardly in the dehydration vessel, and are subjected to a counter-current wash at the bottom of the vessel.

Abstract: Particlized mineral material, such as gold ore, silver ore, or coal, is subjected to a leaching process in a manner to maximize treatment effectiveness even when the particlized mineral material contains small fines. The material is slurried with a flocculating material and fibers, such as cellulosic fibers, fiberglass fibers, or ceramic fibers, and a liquid, and then is passed to the top of a leaching reactor. The slurry is continuously passed downwardly in the reactor while the leaching liquid, such as a cyanide solution, is passed counter-current to the slurry. Leaching liquid is removed from the top of the leaching reactor by a stilling well, and then passed through a carbon adsorber and reintroduced into the reactor. Leached slurry is passed to a continuous washing station being utilized as a slurrying liquid for the particlized mineral material.