Abstract:
The invention provides a process for removing cyanide from a cyanide-bearing aqueous fluid, the process comprising: (i) adding a solid composition comprising a first mixed-metal cyanide complex comprising copper and iron to a cyanide-bearing aqueous fluid comprising free cyanide and metal-complexed cyanide, wherein at least a portion of the first mixed-metal cyanide complex dissolves, with complexation of the copper by the free cyanide, to produce an aqueous solution comprising cyanometallates, the cyanometallates comprising copper cyanide and iron cyanide complexes derived from the first mixed-metal cyanide complex; (ii) contacting the aqueous solution with an anion-exchange absorbent to absorb the cyanometallates, thereby producing a cyanide-lean aqueous fluid; (iii) extracting the anion-exchange absorbent comprising the absorbed cyanometallates with at least one non-acidic aqueous extractant to produce an aqueous extract comprising the copper cyanide and iron cyanide complexes; and (iv) acidifying the aqueous extract to produce a precipitate comprising a second mixed-metal cyanide complex comprising copper and iron.
Abstract:
A method is provided for synthesizing a metal-doped transition metal hexacyanoferrate (TMHCF) battery electrode. The method prepares a first solution of A x Fe(CN) 6 and Fe(CN) 6 , where A cations may be alkali or alkaline-earth cations. The method adds the first solution to a second solution containing M-ions and M`-ions. M is a transition metal, and M` is a metal dopant. Subsequent to stirring, the mixture is precipitated to form A x M c M` d Fe z (CN) n .mH 2 O particles. The A x M c M` d Fe z (CN) n .mH 2 O particles have a framework and interstitial spaces in the framework, where M and M` occupy positions in the framework. Alternatively, the method prepares A a A` b M y Fe z (CN) n .mH 2 O particles. A and A` occupy interstitial spaces in the A a A` b M y Fe z (CN) n .mH 2 O particle framework. A metal-doped TMHCF electrode is also provided.
Abstract:
The invention provides a process for the production of iron based pigments and anticorrosive additives from elemental iron comprising: a) reacting iron Fe DEG with ferric sulphate Fe2(SO4)3 and with sulfuric acid H2SO4 to produce ferrous sulphate FeSO4; b) oxidizing ferrous sulphate FeSO4 in a bacterial solution containing at least 10 bacterial cells of thiobacillus ferrooxidans per 1 ml of solution under aerobic conditions to produce ferric oxide sulphate Fe2(SO4)3; c) reacting said ferric oxide sulphate Fe2(SO4)3 with water, to precipitate iron oxide monohydrate Fe2O3 x H2O; and d) re-cycling the solution from step c, to step a, to utilize the sulphuric acid and a portion of the ferrous sulphate values therein.
Abstract translation:本发明提供了一种从元素铁生产铁基颜料和防腐添加剂的方法,包括:a)使铁Fe DEG与硫酸铁Fe 2(SO 4)3和硫酸H 2 SO 4反应生成硫酸亚铁FeSO4; b)在需氧条件下,每1ml溶液中含有至少10 7个硫氧化硫杆菌细菌细菌的细菌溶液中硫酸亚铁FeSO 4氧化产生硫酸铁Fe2(SO4)3; c)使所述氧化铁硫酸盐Fe 2(SO 4)3与水反应,以沉淀氧化铁一水合物Fe 2 O 3·H 2 O; 和d)将来自步骤c的溶液重新循环到步骤a,以利用其中的硫酸和一部分硫酸亚铁值。
Abstract:
There is disclosed is a compound of formula (I): Na 2-x Fe 2-w (CN) 6-y .(Vacancy) v .zH 2 O, which compound is provided in the form of a monoclinic lattice system, and where v, w, x, y and z are as defined herein. Methods of making this material and its use to form electrodes for sodium ion batteries are also disclosed. In addition, the compound of formula (I) can be converted into a compound of formula (II) in a rhombohedral lattice system: Na 2-x' Fe 2-w' (CN) 6-y' .(Vacancy) v' .z'H 2 O by a further method disclosed herein, where v', w', x', y' and z' for the compounds of formula (II) are as defined herein. The use of compounds of formula (I) in the formation of electrodes for sodium ion batteries and electrodes comprising compounds of formula (II) prepared from converting electrodes comprising compounds of formula (I) are also disclosed.
Abstract:
Electrolyte solutions for flow batteries and other electrochemical systems can contain a dissolved iron hexacyanide complex as an active material. Alkaline buffering can be desirable in such electrolyte solutions to promote stability of the active material. However, the buffer material can undesirably decrease solubility of the iron hexacyanide complex to unacceptable levels in some instances. Compositions with increased concentrations of iron hexacyanide can include an aqueous solution containing a dissolved iron hexacyanide complex, and a solid buffer material in contact with the aqueous solution. The solid buffer material is present at an amount greater than that needed to produce a saturation concentration of the solid buffer material in the aqueous solution. Flow batteries and other electrochemical systems can contain the compositions as an electrolyte solution. Electrolyte solutions containing active materials other than an iron hexacyanide complex can also be stabilized by using an appropriate solid buffer material.
Abstract:
A method is provided for synthesizing sodium iron(II)-hexacyanoferrate(II). A Fe(CN) 6 material is mixed with the first solution and either an anti-oxidant or a reducing agent. The Fe(CN) 6 material may be either ferrocyanide ([Fe(CN) 6 ] 4- ) or ferricyanide ([Fe(CN) 6 ] 3- ). As a result, sodium iron(II)-hexacyanoferrate(II) (Na 1+X Fe[Fe(CN) 6 ] Z .mH 2 O is formed, where x is less than or equal to 1, and where m is in a range between 0 and 7. In one aspect, the first solution including includes A ions, such as alkali metal ions, alkaline earth metal ions, or combinations thereof, resulting in the formation of Na 1+X A Y Fe[Fe(CN) 6 ] Z .mH 2 O, where y is less than or equal to 1. Also provided are a Na 1+X Fe[Fe(CN) 6 ] Z .mH 2 O battery and Na 1+X Fe[Fe(CN) 6 ] Z .mH 2 O battery electrode.
Abstract:
Stable solutions comprising charged coordination complexes, including iron hexacyanides are described, as are methods of preparing and using same in chemical energy storage systems, including flow battery systems. The use of these compositions allows energy storage densities at levels unavailable by other iron hexacyanide systems.