(2) Patent Application Publication (10) Pub. No.: US 2016/0194771 A1 SCHUFFER AMELLER (43) Pub
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US 20160194771A1 (19) United States (2) Patent Application Publication (10) Pub. No.: US 2016/0194771 A1 SCHUFFER AMELLER (43) Pub. Date: Jul. 7, 2016 (54) USE OF OXYGENATED OR Publication Classification POLYOXYGENATED WEAKACIDS, OR MINERALS, COMPOUNDS ORDERIVATIVES (51) Int. Cl. C25C I/IX (2006.01) THAT GENERATE SAME, IN COPPER (52) U.S. CI. ELECTROWINNING PROCESSES IN CPC ..…. C25C 1/12 (2013.01) CATHODES OR ANODES OF ELECTROLYTIC CELLS, ORIGINATING (57) ABSTRACT FROM THE LEACHING OF A COPPER The invention relates to the use of oxygenated or polyoxy MINERAL genated weak acids, or minerals or compounds that generate the same to stabilize and buffer the electrolyte solution, (71) Applicant: QUIBORAX S.A., Vitacura, Santiago thereby improving its conductivity, and/or catalytically pro (CL) moting copper electrodeposition. Additionally, a copper electrowinning procedure is described (72) Inventor: Carlos SCHUFFER AMELLER, Arica that comprises the addition of a necessary quantity of an (CL) oxygenated or polyoxygenated weak acid, or mineral or com pound that generates the same, to the electrodeposition pro (21) Appl. No.: 14/758,152 cess; wherein the necessary quantity of weak acid will depend on the characteristics of the mineral, the electrolyte solution, (22) PCT Filed: Dec. 27, 2013 and the current density used. In the invention, the addition of oxygenated or polyoxygen (86) PCT No.: PCT/CL2013/000098 ated weak acids, minerals, compounds or derivatives that § 371 (c)(1), generate the same to the charged electrolytes coming from the (2) Date: Jun. 26, 2015 solvent extraction phase and entering the electrowinning (EW) stage serves the purpose of homogenizing the current (30) Foreign Application Priority Data density within the electrolytic cell, resulting in increased electrical energy consumption efficiency versus the amount Dec. 28, 2012 (CL) ..… 3726-2012 of copper deposited. Patent Application Publication Jul. 7, 2016 Sheet 1 of 2 US 2016/0194771 A1 Figure 1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ r 3. ?urrett density A.3. Patent Application Publication Jul. 7, 2016 Sheet 2 of 2 US 2016/0194771 A1 Figure 2 £attent density Ajmº US 2016/0194771 A1 Jul. 7, 2016 USE OF OXYGENATED OR ers. Filters are used to achieve a better effect with two units POLYOXYGENATED WEAKACIDS, OR (electrowinning cells), instead of one. MINERALS, COMPOUNDS OR DERIVATIVES [0012] b) Electrical connection characteristics: Electrow THAT GENERATE SAME, IN COPPER inning cell electrical connections are very simple, since they ELECTROWINNING PROCESSES IN attempt to reduce the distances from rectifiers in direct cur CATHODES OR ANODES OF rent and high voltage. ELECTROLYTIC CELLS, ORIGINATING [0013] The energy requirements, particularly for electrical FROM THE LEACHING OF A COPPER current, necessary for the electrowinning process are signifi MINERAL cantly high compared to other types of industries. The inven tion is directed to make electrical energy consumption in [0001] The invention relates to the use of oxygenated or copper mining more efficient, particularly in the electrowin polyoxygenated weak acids, minerals, compounds or deriva ning process, thereby solving a problem widely recognized in tives that generate the same, at any degree of concentration, in the industry. copper electrowinning processes in cathodes or anodes of [0014] Metal electrowinning is governed by Faraday’s electrolytic cells from an electrolyte charged with copper Law, which states that: sulfate originating from the leaching of a copper mineral. [0015] The amount of chemical change produced by an [0002] The invention relates to the addition of oxygenated electrical current, i.e., the dissolved ordeposited amount or polyoxygenated weak acids, minerals, compounds or of a substance, is proportional to the amount of electric derivatives that generate the same, to the charged electrolytes ity passed. coming from the solvent extraction phase and entering the electrowinning (EW) stage in order to homogenize the cur [0016] The amounts of various substances deposited or rent density within the electrolytic cell, resulting in increased dissolved by the same amount of electricity are propor electrical energy consumption efficiency versus the amount tional to their equivalent chemical weights. of copper deposited. [0017|| Faraday’s Law states: [0003] Electrowinning (EW) or electrodeposition is one of the processes to recover-in pure form and selectively-metals that are in solution, and consists of recovering the metal from md = ºrrº. = QTC – CFl a properly conditioned leach solution (electrolyte solution), and depositing it on a cathode using an electrolysis process. [0004] In the copper production process, electrowinning is [0018] Where: a highly relevant stage, as copper for industrial use requires a [0019] md=mass deposited [mass/time] purity grade established by electrolytic copper standards. [0020 P., Emolecular weight of the element in study [0005] In the electrowinning (EW) process, a direct electric [0021] iºn-current density of the cell current of low voltage and high intensity circulates through [0022] A.-total area exposed to deposition the electrolytic solution between an anode, the solution itself, [0023] t-exposure time and a cathode. In this way, the metalions of interest (cations) [0024] m. current efficiency (90-92%) are attracted to the cathode (negatively charged pole), where [0025] Z=number of electrons exchanged in the deposition they are deposited, and the impurities are dissolved in the reaction. electrolyte solution, or are precipitated as residue or anode [0026] F=Faraday constant (96.500[c/g-eq] slimes. [0027] Q=solution volumetric flow [0006] Through the electrowinning process, it is possible to [0028] [C-CA-change in concentration of the element of recover metals-such as copper, gold, and silver-from leach interest in the electrowinning stage. able resources that would otherwise be unfeasible. [0029] The role played by oxygenated or polyoxygenated [0007] The processes of purification and concentration of weak acids-such as boric acid or orthophosphoric acid-, min leach solutions, such as solvent extraction (SX) for copper erals, compounds or derivatives of the same, at any degree of and activated carbon (AC) for gold, have broadened the scope concentration in the electrowinning processes of metalions in of application of the electrowinning process to recover these cathodes has a relationship with stabilizing and buffering the metals. So much so that some metals, like zinc, rely almost electrolyte solution, improving its conductivity, especially in exclusively on electrowinning to achieve a recovery that is near-surface electrode layers, as well as catalytically promot economically viable. ing electrodeposition, even in processes with high current [0008] The electrowinning process is also a very competi intensity and high speed cation deposition. tive alternative to treat copper-cobalt and nickel-cobalt com [0030] Additionally, it controls and stabilizes the system’s bined minerals. hydrogen ion discharge, as well as the homogenous distribu [0009] To perform the electrowinning process, electrolytic tion of current in the electrolytic cell, making current use cells with electric circuitry are required to circulate a direct more efficient. electric current of low voltage and high intensity. [0031] The invention relates to the use of oxygenated or [0010) So that the process is carried out efficiently, the polyoxygenated weak acids, preferably, but not limited to following aspects must be considered: boric acid and orthophosphoric acid in the copper electrow [0011] a) Circuit Configuration: To provide the direct cur inning process in order to homogenize the current density in rent required by the electrolysis process, current rectifier the electrolytic cell, resulting in increased electrical energy equipment is used to maintain constant electrical flow char consumption efficiency versus the amount of copper depos acteristics. The technology of rectifiers has evolved, and cur ited. rently uses transistorized transformer rectifiers. The filter [0032] The invention also relates to a copper electrowin requirements for harmonic current control currently consti ning process using oxygenated or polyoxygenated weak acid, tute the major factors in the increasing costs of these rectifi or a mineral or compound that generates the same on the spot, US 2016/0194771 A1 Jul. 7, 2016 whereby increased electrical energy consumption efficiency novskite, kuksite, lacroixite, landesite, laubmanite, laueite, versus the amount of copper deposited is achieved. lazulite, lehnerite, lermontovite, leucophosphite, libethenite, [0033] In the invention, boric acid refers to HaBOs (triox likasite, lipscombite, liroconite, lithiophilite, lithiophospha oboric (III) acid, B(OH)3, also called orthoboric acid), or their tite, lithiophosphate, lomonosovite, ludlamite, luneburgite, derivatives. Boron minerals refers, without limitation, to magniotriplite, mahlmoodite, mangangordonite, maricite, ulexite, colemanite, kernite, pandermite, bakerite, datolite, matulaite, metaankoleite, metaswitzerite, metatorbenite, elbaite, admontite, aksaite, ameghinite, ammonioborite, metavariscite, metavauxite, mimetite, mitridatite, monazite, aristarainite, avogadrite, aximite, bandylite, barberiite, behier monetite, montebrasite, montgomerite, moraesite, ite, berborite, biringuccite, boracite, boralsilite, borax, bora moreauite, morinite, mundite, nabaphite, nafedovite, mali zon, borcarite, bormuscovite, cahnite, calciborite,