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The management of post-stroke complications plays an important role in the quality of life. Di-Tan Decoction (DTD; ) is a widely used traditional Chinese medicine. This study incorporated systematic review and meta-analysis to evaluate the efficacy of DTD in post-stroke neurological disorders. Randomized clinical trials (RCTs) were searched from English, Chinese and Korean electronic medical databases, by including the keywords "Di-Tan Tang", "Di-Tan Decoction", "Scour Phlegm Decoction", "stroke", and "RCT. Each RCT included control (placebo, conventional therapy, or Western medicine) and experimental (DTD treatment) groups. For patients inflicted with stroke for 1-6 weeks, the outcomes of post-stroke neurological disorders were measured by scales for post-stroke symptoms and were classified as "completely healed", "markedly effective", "effective" and "ineffective". Totally, 11 RCTs (n = 490 controls and n = 502 DTD subjects) were selected from 210 articles identified in the initial search. A meta-analysis of evaluation criteria in post-stroke symptoms revealed that the overall odds ratio (ORs) for alleviating post-stroke neurological disorders were 0.30-fold lower (95% CI = 0.21-0.43) in the DTD group than the control (Western medicine) group (P < 0.000 01). Moreover, regardless of the type of stroke diagnostic scale applied (including NFA, HDS, and NIHSS), the overall post-stroke symptoms determined were less severe in the DTD group (n = 219) than the control group (n = 217). No adverse effects of DTD were observed in the 11 RCTs reviewed. All 11 studies used an appropriate method for randomization of subjects to evaluate the risk of bias (ROB), and 7 studies included allocation concealment as well as blinding of patients and practitioners. High-risk ROB was included in 6 RCTs. No significant publication bias was derived from the funnel plot. Our results indicate that the administration of DTD alone, and DTD in combination with Western medicine, exert greater efficacy for post-stroke complication therapy, than Western medicine administered alone. More rigorous and regulated studies are required to confirm the therapeutic efficacy of DTD for post-stroke neurological disorders. disorders.

A sulfuric acid system was used to recover Co from cobalt white alloy, and the leached cobalt was electrochemically dissolved.i This is a key step to separate the iron-silicon alloy phase from valuable metals when leaching cobalt white alloys with high silicon and iron contents. As an additive, sodium hypochlorite (NaClO) acts as an oxidant to break cobalt encapsulation and enhances leaching. It generates chloride ions, which further enhance Co leaching based on their corrosive ability. The results showed that the maximum leaching ratio of Co from the waste cobalt white alloy was 97.76%. Kinetic analysis showed that the apparent activation energy of Co leaching was 34.58 kJ/mol, and the surface chemical reaction was a controlling step for this process. The kinetic equation for the leaching of Co can be expressed as $$1 - \left( {1 - \alpha } \right)^{\frac{1}{3}} = 0.065t \times \left( {r_{0}^{ - 1} } \right) \times \left[ {{\text{H}}_{2} {\text{SO}}_{4} } \right]^{2.44} \times \exp \left( {\frac{ - 34580}{{8.314T}}} \right)$$ .

Rubidium in muscovite was selectively extracted using a chlorination roasting-water immersion method. The experimental results revealed that the chlorination effects of this metal were best when the roasting temperature was 800 °C. After 30 min of water immersion, the extraction rate of rubidium was the highest (96.71%), and XRD and SEM-EDS were used to analyze the migration transformation of elements and the phase changes that occurred during the chlorination roasting process. Finally, the non-isothermal kinetics of the muscovite chlorination roasting process was investigated via TG-DTA. The results revealed that the most probable mechanism for this process in non-isothermal conditions was the 3-D diffusion (Z-L-T) model with the integral form with g(a) = [(1-α)-1/3–1]2. The activation energy was determined to be 216.92 kJ·mol−1. Furthermore, the kinetic equation for fitting the results was formulated.

The potential autoclave was used to study the catalytic mechanism of Cu2+ during the oxygen pressure leaching process of artificial sphalerite. By studying the potential change of the system at different temperatures and the SEM-EDS difference of the leaching residues, it was found that in the temperature range of 363–423 K, the internal Cu2+ formed a CuS deposit on the surface of sphalerite, which hindered the leaching reaction, resulting in a zinc leaching rate of only 51.04%. When the temperature exceeds 463 K, the system potential increases steadily. The increase in temperature leads to the dissolution of the CuS, which is beneficial to the circulation catalysis of Cu2+. At this time, the leaching rate of Zn exceeds 95%. In addition, the leaching kinetics equations at 363–423 and 423–483 K were established. The activation energy of zinc leaching at 363–423 and 423–483 K is 38.66 and 36.25 kJ/mol, respectively, and the leaching process is controlled by surface chemical reactions.

The oxygen pressure leaching of sphalerite in sulphuric acid solutions is a slow process in the absence of iron because of the limitations of the oxygen delivery carrier (redox couple: Fe3+/Fe2+). ...

The mechanism of oxygen pressure acid leaching of sphalerite catalyzed by Fe3+/Fe2+ self-precipitation was investigated in this study. Artificial sphalerite was fabricated with varying amounts of iron content via the sintering of ZnS and FeS and used for the pressure acid leaching experiment. The variations in the potential of the pressure leaching system were investigated by using a self-designed potential autoclave. The results showed that compared to the non-iron sphalerite, there was a violent redox reaction between the 25.70% Fe-artificial sphalerite and dissolved oxygen during the process of pressure leaching; and the catalytic mechanism was attributed to the redox couple Fe3+/Fe2+, where Fe3+oxidizes the H2S gas film and the reduced Fe2+ state is subsequently oxidized by the dissolved oxygen. Furthermore, the effect of temperature, H2SO4 concentration, and oxygen partial pressure on the artificial sphalerite with different iron contents was studied. The sphalerite samples with iron content were observed to dissolve more easily in sulfuric acid compared to the non-iron samples. Moreover, the activation energy of artificial sphalerite was observed to be lower in the sample with 25.70% iron content (22.26 kJ/mol) compared to that with no iron (32.31 kJ/mol); and the apparent reaction orders were obtained with respect to H2SO4 concentration (1.10 and 1.36) and oxygen partial pressure (1.29 and 1.41), respectively. A comprehensive kinetic model was developed on the basis of the experimental data and the fitted leaching ratio plot; and the kinetic equations for the leaching of sphalerite catalyzed by Fe3+/Fe2+ self-precipitation were determined.

This paper proposes an innovative carbothermal reduction roasting low-carbon redox refining process for recovering valuable metals, including copper, zinc, nickel, tin and lead, from electroplating sludge. First, the valuable metals are volatilized into the flue gas by carbothermal reduction roasting. At a reduction temperature of 1473 K, a carbon content of 20%, and a reaction time of 60 min, the ratio of Pb, Sn and Zn removal reached 90.77%, 95.14% and 99.92%, respectively. At an oxidation temperature of 1573 K, a SiO2 content of 6% and a reaction time of 180 min, a water-quenching slag suitable for building materials was obtained by low-carbon oxidation reduction refining. Finally, at a reduction temperature of 1473 K, 8% C addition, and a reaction time of 20 min, copper and nickel were enriched on an anode copper plate and the copper content reached more than 98%, meeting the requirements for copper electrolysis.

To solve the problem of rare earths (RE) lithium (Li) and fluorine (F) recovery in rare earth molten salt electrolysis slag, a recovery method was developed based on magnetic separation, sulfuric acid leaching, HF recycling, water leaching, fluorination precipitation. First, RE, Li and iron-containing phases in a slag sample were separated using a magnetic separation method. Second, sulfuric acid-leaching was used to reconstruct the phases of RE and Li in the non-magnetic fraction, which were transformed into a rare earth sulfate easily dissolved in water. At the same time, the HF generated in the sulfuric acid leaching process is recovered by multistage adsorption. Finally, qualified fluoride rare earth products were obtained by HF cycle precipitation. The results show that the recovery of iron is 85.30% under the condition that the magnetic separation intensity of 0.668 T, particle size of 58–75 μm, and the main phase in the non-magnetic fraction is the rare earth phase, and the iron content is only 2.90%. Under the conditions of a concentrated acid concentration of 98.00%, a temperature of 633 K, a liquid–solid ratio of 2:1, a particle size of 58–75 μm, a constant stirring speed of 300 r·min−1, and reaction time of 3 h, the removal rate of F is 95.30%, and the transformation rates of Nd, Pr, Dy, and Li reached more than 95.00%. Through water immersion and fluorination precipitation, rare earth fluoride products can be obtained. The purity, particle size, and water content of the products met the standards required for industrial rare earth molten salt electrolysis.