Low-temperature chlorination roasting technology for the simultaneous recovery of valuable metals from spent LiCoO_(2)cathode material

With the continuous increase in the disposal volume of spent lithium-ion batteries(LIBs),properly recycling spent LIBs has become essential for the advancement of the circular economy.This study presents a systematic analysis of the chlorination roasting kinetics and proposes a new two-step chlorination roasting process that integrates thermodynamics for the recycling of LIB cathode materials.The activation energy for the chloride reaction was 88.41 kJ/mol according to thermogravimetric analysis–derivative thermogravimetry data obtained by using model-free,model-fitting,and Z(α)function(αis conversion rate).Results indicated that the reaction was dominated by the first-order(F1)model when the conversion rate was less than or equal to 0.5 and shifted to the second-order(F2)model when the conversion rate exceeded 0.5.Optimal conditions were determined by thoroughly investigating the effects of roasting temperature,roasting time,and the mass ratio of NH_(4)Cl to LiCoO_(2).Under the optimal conditions,namely 400℃,20 min,and NH_(4)Cl/LiCoO_(2)mass ratio of 3:1,the leaching efficiency of Li and Co reached 99.43% and 99.05%,respectively.Analysis of the roasted products revealed that valuable metals in LiCoO_(2)transformed into CoCl_(2) and LiCl.Furthermore,the reaction mechanism was elucidated,providing insights for the establishment of a novel low-temperature chlorination roasting technology based on a crystal structure perspective.This technology can guide the development of LIB recycling processes with low energy consumption,low secondary pollution,high recovery efficiency,and high added value.

Extraction of lithium from lepidolite using chlorination roasting-water leaching process

Chlorination roasting followed by water leaching process was used to extract lithium from lepidolite.The microstructure of the lepidolite and roasted materials were characterized by X-ray diffraction（XRD）.Various parameters including chlorination roasting temperature,time,type and amount of chlorinating agents were optimized.The conditional experiments indicate that the best mass ratio of lepidolite to NaCl to CaCl2 is 1：0.6：0.4 during the roasting process.The extraction of lithium reaches peak value of 92.86% at 880 °C,potassium,rubidium,and cesium 88.49%,93.60% and 93.01%,respectively.The XRD result indicates that the major phases of the product after roasting lepidolite with mixture of chlorinating agents（CaCl2 and NaCl） are SiO2,CaF2,KCl,CaSiO3,CaAl2Si2O8,NaCl and NaAlSi3O8.

Simultaneous extraction of gold and zinc from refractory carbonaceous gold ore by chlorination roasting process

A novel process based on chlorination roasting was proposed to simultaneously recover gold and zinc from refractory carbonaceous gold ore by using NaCl as chlorination agent.The effects of roasting temperature,roasting time and NaCl content on the volatilization rates of gold and zinc were investigated.The reaction mechanism and the phase transition process were also analyzed by means of SEM,EDS and XRD.The results demonstrated that under the optimal conditions of NaCl content of 10%,roasting temperature of 800℃,roasting time of 4 h and gas flow rate of 1 L/min,the rates of gold and zinc were 92%and 92.56%,respectively.During low-temperature chlorination roasting stage,a certain content of sulfur was beneficial to the chlorination reactions of gold and zinc;and during high-temperature chlorination roasting stage,the crystal structure of vanadium-bearing mica was destroyed,and the vanadium-containing oxides were beneficial to the chlorinating volatilization of gold and zinc.Eventually,the chlorinated volatiles of gold and zinc could be recovered by alkaline solution.

Thermodynamic analysis and process optimization of zinc and lead recovery from copper smelting slag with chlorination roasting

An efficient chlorination roasting process for recovering zinc(Zn)and lead(Pb)from copper smelting slag was proposed.Thermodynamic models were established,illustrating that Zn and Pb in copper smelting slag can be efficiently recycled during the chlorination roasting process.By decreasing the partial pressure of the gaseous products,chlorination was promoted.The Box−Behnken design was applied to assessing the interactive effects of the process variables and optimizing the chlorination roasting process.CaCl_(2) dosage and roasting temperature and time were used as variables,and metal recovery efficiencies were used as responses.When the roasting temperature was 1172℃ with a CaCl_(2) addition amount of 30 wt.%and a roasting time of 100 min,the predicted optimal recovery efficiencies of Zn and Pb were 87.85%and 99.26%,respectively,and the results were validated by experiments under the same conditions.The residual Zn-and Pb-containing phases in the roasting slags were ZnFe_(2)O_(4),Zn_(2)SiO_(4),and PbS.

Chlorination roasting-coupled water leaching process for potash recovery from waste mica scrap using dry marble sludge powder and sodium chloride

The present paper reports the effective utilization of marble sludge powder(MSP)for the recovery of potash values from waste mica scrap using chlorination roasting-water leaching method.Characterization studies indicated the presence of dolomite as the major mineral phase in MSP,whereas muscovite and quartz were observed in the mica sample.The acid leaching studies suggest a maximum of 22%potash recovery under conditions:4 M H2SO4 acid,particle size of^100μm,stirring speed of 600 r/min,leaching temperature of 75℃,and leaching time of 90 min.The chlorination roasting-water leaching process was adopted to achieve the lowest level of 80%-90%potash recovery.The optimum conditions for the recovery of^93%potash from mica(~8.6wt%K2O)requires 900℃ roasting temperature,30 min roasting time,and 1:1:0.75 mass ratio of mica:MSP:NaCl.The roasting temperature and amount of NaCl are found to be the most important factors for the recovery process.The reaction mechanism suggests the formation of different mineral phases,including sylvite(KCl),wollastonite,kyanite,and enstatite,during roasting,which were confirmed by X-ray diffraction(XRD)analyses and scanning electron microscopy(SEM)morphologies.The MSP-blended NaCl additive is more effective for potash recovery compared with the other reported commercial roasting additives.

Process Optimization and Reaction Mechanism of Removing Copper From an Fe-Rich Pyrite Cinder Using Chlorination Roasting

The aim is to remove copper from a pyrite cinder by optimizing the chlorination roasting process using re-sponse surface methodology （RSM） and the reaction mechanism of chlorination roasting based on thermodynamic calculation was discussed. A quadratic model was suggested by RSM to correlate the key parameters, namely, dos-age of chlorinating agent, roasting temperature and roasting time to the copper volatilization ratio. The results indi- cate that the model is well consistent with the experimental data at a correlation coefficient （R2） of 0.95, and the dosage of chlorinating agent and roasting temperature both have significant effects on the copper volatilization ratio. However, a roasting temperature exceeding 1170 ~C decreases the volatilization ratio. The optimum conditions for removing copper from the cinder were identified as chlorinating agent dosage at 5%, roasting temperature at i155.10 ℃ and roasting time of 10 min; under Such a conditiom a copper volatilization ratid of 95.16% Was a- chieved from the cinder. Thermodynamic calculation shows that SiO2 in the pellet plays a key role in the chlorine re-lease from calcium chloride, and the chlorine release reactions cannot occur without it.

Reaction characteristics and kinetics of gallium in chlorination roasting of copper tailings using calcium chloride

The mineral composition of copper tailings was examined, and the phase analysis of gallium was conducted for recovery of the rare scattered metal gallium from copper tailings. The reaction characteristics and kinetics of gallium in the chlorination roasting of copper tailings were investigated in a tube furnace apparatus under different conditions, including roasting temperature, quantity of chlorination agent,roasting time, and airflow. Calcium chloride was chosen for the chlorination reaction because it is highly effective for volatilization of metals. The results show that gallium mainly exists in limonites in the form of oxides, and increases in roasting temperature, quantity of chlorination agent, and roasting time are conducive to increasing the chloridizing volatilization rate of gallium. The tailings gradually melt when the roasting temperature exceeds 900℃, resulting in a decrease in the chloridizing volatilization rate of gallium. The chloridizing volatilization rate of gallium reaches 78.86%at roasting temperature of 900℃ for 40 min, airflow of 0.1 m^(3)·h^(-1), and calcium content of 33.33 wt%. Study of the reaction kinetics of gallium in chlorination roasting shows that the values of activation energy both for chemically controlled anddiffusion-controlled reactionsare44.64and11.93 kJ·mol^(-1), respectively. This indicates that the chemical reaction serves an important function in the chlorination volatilization of gallium. Taken together, the results reveal the usefulness of tailings as a source of rare metals and provide a basis for gallium recovery and environmentally friendly disposal of copper tailings.

Co-extraction of valuable metals and kinetics analysis in chlorination process of low-grade nickel-copper sulfide ore

To efficiently co-extract Ni and Cu from low-grade nickel-copper sulfide ore,chlorination roasting with NH;Cl followed by a water leaching process was investigated.The results show that 98.4%Ni and 98.5%Cu can be synchronously extracted when the ore particle size is 75-80μm,the roasting time is 2 h,the mass ratio of NH;Cl to ore is 1.6:1 and the roasting temperature is 550°C.The evolution behavior of various minerals was elucidated using X-ray diffraction(XRD)coupled with scanning electron microscopy(SEM).The kinetics of the chlorination process based on the differential thermal and thermogravimetric analysis(DTA-TG)data was analyzed by Kissinger method and Flynn-Wall-Ozawa(FWO)method.The chlorination process of low-grade nickel-copper sulfide ore mainly contains two stages:the decomposition of NH;Cl and the chlorination of ore.The maximum apparent activation energies(Ea)at two stages are determined to be 114.8 and 144.6 kJ/mol,respectively.The condensed product of exhaust gas is determined to be ammonium chloride,which can be recycled as the reactant again,making the process economic and clean.

Crystal structure transformation and lattice impurities migration of quartz during chlorine roasting OA

To investigate the effect of chlorine roasting on the migration and removal of trace elements in quartz lattice,firstly,an efficient pretreatment process,grinding–HCl washing–flotation–HF and HCl leaching,was used to remove the gangue minerals in quartz ore to obtain purified quartz for the preparation of high-purity quartz and the investigation of lattice impurities migration.The results showed that the high-purity quartz with total impurities less than 50μg/g could be obtained from purified quartz after being treated with chlorine at 1200°C.The variation of crystal structure and the lattice impurities migration of quartz during chlorine roasting were studied through in-situ XRD,TGA,SEM-EDS,ICP-MS,FT-IR and XPS analysis.It revealed that the decomposable impurities H_(2)O,-OH,and residual collectors in the crystal of purified quartz could be effectively removed through chlorine roasting above 900°C,which also had an obvious effect on the removal of low-valence trace elements Li,Na and K in the crystal of quartz but didn't affect the multivalent trace elements Al and Ti.This study revealed the removal and migration mechanism of the trace elements in quartz crystal during chlorine roasting.