Utilization Of Magnesium Research Articles

A process to utilize lithium and magnesium resources from low-magnesium salt lake brine through extraction and CO2 stripping

The lithium resources in Tibet's salt lake account for more than 31 % of China's total, featuring a low magnesium-to-lithium ratio with its carbonate-type salt lakes representing a unique resource of the region. When extracting lithium from low-magnesium salt lakes (carbonate-type salt lakes) using a β-diketone system, it is common practice to add alkaline reagents at the front end to precipitate and remove magnesium. This study utilizes the LIX54/TRPO-ADD-1 system for the co-extraction of lithium and magnesium from the brine of the Jiezechaka salt lake, employing CO2 for stepwise stripping to separate lithium and magnesium, using a weak acid instead of a strong acid for stripping to avoid impacting Tibet's fragile ecological environment. By controlling the pH with varying amounts of CO2, an extraction efficiency of 92.54 % for lithium at pH=8.5 and an A/O = 1:5, and complete stripping of magnesium from the loaded organic phase at pH=7 with an A/O = 1:3.2 over three theoretical stages was achieved. This new process omits the front-end magnesium precipitation step, offering a new avenue for the separation of lithium and magnesium in salt lakes and the resource utilization of magnesium.

Magnesium Utilization in Dolomite Rocks by Struvite Precipitation in an Insulated Column Reactor

Dolomite is a natural mineral rock with the chemical formula CaMg(CO3)2. Pure dolomite contains 21.70% calcium and 13.04% magnesium. Dolomite has not been widely used in the industrial sector until now. One way to increase the economic value of dolomite rock is to utilize its magnesium content as a precursor to struvite mineral which is the raw material for slow release fertilizer. Under alkaline conditions, struvite minerals are formed at concentrations of Mg2+, NH4+, and PO43-. Struvite solution (MAP) can be prepared by reacting phosphoric acid, ammonium hydroxide, and dolomite as a magnesium source in a molar ratio of 1:1:1. In a continuously operated isolated column reactor, the pH ranged from 8 to 12, and the reactor inlet air velocity ranged from 0.25 to 1.25 L/min. The chemical elements of dried struvite were determined using XRF (X-Ray Fluorescence), and the morphology was analyzed using SEM (Scanning Electron Microscope). At the same time, the crystal phase composition was identified using the Rietveld XRD (X-Ray Diffraction) technique. Based on the results of XRF analysis, the highest magnesium content was found under operating conditions with pH 12, air rate 0.75 L/min, and magnesium content 15.5%.

Industrial Ecotechnological Assessment of Lime as a Sustainable Substitute for Desulfurization of Cast Iron

This study comprehensively assesses the ecotechnological consideration and perspective of implementing a lime-based desulfurization process in the cast iron industry to replace the utilization of magnesium partially. By adopting an injection process to introduce the lime powder into molten cast iron, this research elucidated that the new alternative concept can successfully be integrated with daily operations without any disparities in cast iron quality, as proved by the production of cast iron products with vermicular graphite. A mixture of lime powder and carbon was utilized, and it was substantiated that the aim of a sulfur content lower than 0.015% can be reliably achieved. Furthermore, an ecological analysis was also conducted to justify the possible environmental advantages. The results indicated that considering the cradle-to-gate approach, the maximum amount of CO2eq connected to the lime-based desulfurization is approximately 43 g for 1 kg of desulfurized cast iron. This amount of calculated emission is still expected to be lower than the minimum calculated emission associated with the magnesium-based process, which can reach an amount of 76 g for a similar functional unit.Graphical

Biomimicking covalent organic frameworks nanocomposite coating for integrated enhanced anticorrosion and antifouling properties of a biodegradable magnesium stent

The utilization of biodegradable magnesium (Mg) alloys in the fabrication of temporary non-vascular stents is an innovative trend in biomedical engineering. However, the heterogeneous degradation profiles of these biomaterials, together with potential bacterial colonization that could precipitate infectious or stenotic complications, are critical obstacles precluding their widespread clinical application. In pursuit of overcoming these limitations, this study applies the principles of biomimicry, particularly the hydrophobic and anti-fouling characteristics of lotus leaves, to pioneer the creation of nanocomposite coatings. These coatings integrate poly-trimethylene carbonate (PTMC) with covalent organic frameworks (COFs), to modify the stent's surface property. The strategic design of the coating's topography, porosity, and self-polishing capabilities collectively aims to decelerate degradation processes and minimize biological adhesion. The protective qualities of the coatings were substantiated through rigorous testing in both in vitro dynamic bile tests and in vivo New Zealand rabbit choledochal models. Empirical findings from these trials confirmed that the implementation of COF-based nanocomposite coatings robustly fortifies Mg implantations, conferring heightened resistance to both biocorrosion and biofouling as well as improved biocompatibility within bodily environments. The outcomes of this research elucidate a comprehensive framework for the multifaceted strategies against stent corrosion and fouling, thereby charting a visionary pathway toward the systematic conception of a new class of reliable COF-derived surface modifications poised to amplify the efficacy of Mg-based stents. Statement of SignificanceBiodegradable magnesium (Mg) alloys are widely utilized in temporary stents, though their rapid degradation and susceptibility to bacterial infection pose significant challenges. Our research has developed a nanocomposite coating inspired by the lotus, integrating poly-trimethylene carbonate with covalent organic frameworks (COF). The coating achieved self-polishing property and optimal surface energy on the Mg substrate, which decelerates stent degradation and reduces biofilm formation. Comprehensive evaluations utilizing dynamic bile simulations and implantation in New Zealand rabbit choledochal models reveal that the coating improves the durability and longevity of the stent. The implications of these findings suggest the potential COF-based Mg alloy stent surface treatments and a leap forward in advancing stent performance and endurance in clinical applications.

Multiscale morphological analysis of bone microarchitecture around Mg-10Gd implants.

The utilization of biodegradable magnesium (Mg)-based implants for restoration of bone function following trauma represents a transformative approach in orthopaedic application. One such alloy, magnesium-10weight percent gadolinium (Mg-10Gd), has been specifically developed to address the rapid degradation of Mg while enhancing its mechanical properties to promote bone healing. Previous studies have demonstrated that Mg-10Gd exhibits favorable osseointegration; however, it exhibits distinct ultrastructural adaptation in comparison to conventional implants like titanium (Ti). A crucial aspect that remains unexplored is the impact of Mg-10Gd degradation on the bone microarchitecture. To address this, we employed hierarchical three-dimensional imaging using synchrotron radiation in conjunction with image-based finite element modelling. By using the methods outlined, the vascular porosity, lacunar porosity and the lacunar-canaliculi network (LCN) morphology of bone around Mg-10Gd in comparison to Ti in a rat model from 4 weeks to 20 weeks post-implantation was investigated. Our investigation revealed that within our observation period, the degradation of Mg-10Gd implants was associated with significantly lower (p<0.05) lacunar density in the surrounding bone, compared to Ti. Remarkably, the LCN morphology and the fluid flow analysis did not significantly differ for both implant types. In summary, a more pronounced lower lacunae distribution rather than their morphological changes was detected in the surrounding bone upon the degradation of Mg-10Gd implants. This implies potential disparities in bone remodelling rates when compared to Ti implants. Our findings shed light on the intricate relationship between Mg-10Gd degradation and bone microarchitecture, contributing to a deeper understanding of the implications for successful osseointegration.

Influence of Alloying Materials Al, Cu, and Ca on Microstructures, Mechanical Properties, And Corrosion Resistance of Mg Alloys for Industrial Applications: A Review.

Magnesium is renowned for its favorable low-density attributes, rendering it a viable choice for commercial engineering applications in which weight has substantial design implications. Magnesium (Mg) stands as a readily obtainable metallic element, exhibiting robustness, efficient heat dissipation, and excellent damping properties. The utilization of pure magnesium remains infrequent due to its susceptibility to instability under high temperatures and pronounced vulnerability to corrosion within humid environments. Hence, the incorporation of magnesium alloys into the design process of aircraft, automotive, and biomedical applications assumes paramount importance. This Review presents a comprehensive review of research endeavors and their resultant achievements concerning the advancement of magnesium alloys. Specifically focusing on aerospace, automotive, and biomedical applications, the Review underscores the pivotal role played by alloying constituents, namely aluminum (Al), copper (Cu), calcium (Ca), and PEO coatings, in influencing the microstructural attributes, mechanical potency, and resistance to corrosion.

SPAD values, as well as sugar- and capsaicin content in different varieties of outdoor peppers

The marketability of the sweet peppers is determined by their quality in Class I, which must also meet the highest standards in terms of the color, shape of the variety and the characteristics of the various flavors. However, the determinants of quality may vary from one pepper type to another. During of our research, we examined the utilization of nitrogen, magnesium and potassium in different types of domestic peppers in the context of the relative chlorophyll content of the foliage and the amount of sugar and total capsaicin in the fruits. We determined that the nutrient solution prepared by Duna-r Ltd. is suitable for achieving the highest sugar and capsaicin content, but their levels can differ significantly. The uptake and utilization of nitrogen, magnesium and potassium of nutrient solution can be checked with the SPAD (Soil Plant Analysis Development) index data of the foliage. We found that there are periods in the phenophase of the pepper cultivars studied when both sugar content and capsaicin content increase significantly. Another major result is that sugar content is a basic determinant of capsaicin content in hot peppers and cherry peppers, while it is not an important factor of capsaicin content for Bogyiszló-type peppers.

Carbon dioxide capture coupled with magnesium utilization from seawater by bipolar membrane electrodialysis

Carbon dioxide (CO2) capture coupled with further mineralization in high value-added form is a great challenge for carbon capture utilization and storage (CCUS) processes. In this work, a bipolar membrane electrodialysis (BMED) technique integrated with crystallization chamber was proposed to utilize CO2-derived carbonates and the residual magnesium resource from seawater to produce functional nesquehonite. To ensure the stable CO2 storage and magnesium extraction by BMED process, the metastable zone during nesquehonite crystallizing was first measured to modulate crystallization rate, obtain high-quality crystal products and inhibit membrane fouling states. Subsequently, the effects of current density, temperature, and CO2 flow rate during the whole BMED-crystallization process were further investigated. The increase in current density and temperature was conducive for the extraction of magnesium while the enlarged gas flow rate induced higher absorption of CO2. Under the current density at 22 A/m2, CO2 flow rate at 50 mL/min and temperature at 30 °C, the optimal carbon absorption ratio and the magnesium extraction ratio reached 50.85% and 56.71%, respectively. Under this condition, the explosion nucleation of the nesquehonite was effectively avoided to inhibit membrane fouling and the generation of magnesium hydroxide was depressed to obtain the target product nesquehonite. This study on simultaneous carbon capture and magnesium utilization provides theoretical guidance for the industrial green storage of CO2 and development of valuable magnesium products.

The Growth-Promoting Mechanism of Brevibacillus laterosporus AMCC100017 on Apple Rootstock Malus robusta

Plant growth-promoting rhizobacteria (PGPR) located in rhizobacteria soil are beneficial to plant growth and development. A PGPR strain AMCC100017 of Brevibacillus laterosporus synthesizes the plant hormone IAA in a tryptophan-dependent manner. In this study, the AMCC100017 strain was used to treat Malus robusta , an excellent natural rootstock for apple production, and assess its ability to promote growth. The fresh weight, dry weight, plant height, and lateral root growth of M. robusta were significantly increased with treatment. The presence of the AMCC100017 strain increased IAA content in M. robusta and promoted root secretion of tryptophan. Colonization of the strain in the roots allowed continuous synthesis of IAA and promoted plant growth. In addition, the photosynthetic efficiency in leaves increased after microbial treatment, and the utilization of nitrogen, zinc, iron, copper and magnesium in leaves was increased, which was conducive to photosynthesis. Interestingly, the activities of CAT and SOD, as well as the contents of ROS in plants colonized by AMCC100017 were increased compared to control plants, but the activities of POD and MDA contents were decreased. AMCC100017 strain affected the antioxidant capacity and stress resistance of plants. AMCC100017 strain increased the content of soluble protein and soluble sugar in plants, improved plant metabolic activity and stress resistance. Therefore, AMCC100017 not only increased IAA content and photosynthetic efficiency to promote M. robusta growth, but also affected plant through multiple metabolic pathways.

Optimization and prediction of AZ91D stellite-6 coated magnesium alloy using Box Behnken design and hybrid deep belief network

Nowadays, the utilization of magnesium (Mg) alloys is increased due to its various beneficial characters such as better thermal conductivity, minimum density, less weight, superior strength, good dimensional, stability nature, etc. They are used in both mechanical as well as electrical industries. In the same way, it is used in electronic industries for its perfect capability of damping and electromagnetic shielding offers noise reduction. Although, they have a lot of advantages some disadvantages surround them. Mg alloy easily corroded when used at certain wet zones and the poor wear behavior may suppress the service life of Mg alloys. To overcome such issues, a surface coating approach is to be carried out on Mg alloy AZ91D using stellite powder to assist with NiCr pre-coating. The coated Mg alloys are studied for their porosity (%), corrosion rate (mm/year), and wear loss (mg). The experimental study is planned by Response Surface Methodology (RSM) using Box Behnken Design (BBD). The outcomes are validated by Hybrid Deep Belief Network (DBN) based Mayfly optimization approach in MATLAB version 2020a. The minimum porosity, corrosion rate and wear loss obtained for the coated AZ91D Mg alloy is 0.588%, 1.302 mm/year, and 0.719 mg. Besides, the hybrid DBN-based predicted outcomes are closer to the experimental outcomes.

Application of magnesium alloys in orthopedic implant

Technological updates in the field of advanced materials research are now tend to focuses on biomedical materials application and utilization of Magnesium and its’ alloys. Magnesium (Mg) has been widely studied as an alternative material for biodegradable orthopedic implant applications. Recent studies regarding the potential application of Mg have been done related to its’ mechanical properties, biodegradation profile, and the in-vitro and in-vivo testing. This study aims to review the Mg properties, production process, biomaterial roadmap, and the concern of chemical composition of Mg alloy in orthopedic application. Future potential improvement of the magnesium alloys properties is also highlighted

Joint Reduction of NiO/WO3 Pair and NiWO4 by Mg + C Combined Reducer at High Heating Rates

Functional features of Ni-W composite materials combined with successful performance enabled a breakthrough in their broad application. To disclose the formation pathway of Ni-W composite materials at extreme conditions of combustion synthesis in the NiO-WO3-Mg-C and NiWO4-Mg-C systems for the optimization of the synthesis procedure, the process was modeled under programmed linear heating conditions by thermal analysis methods. The reduction kinetics of tungsten and nickel oxides mixture and nickel tungstate by Mg + C combined reducer at non-isothermal conditions was studied at high heating rates (100–1200 °C min−1) by high-speed temperature scanner techniques. It was shown that when moving from low heating to high heating rates, the mechanism of both the magnesiothermic and magnesio-carbothermic reductions of the initial mixtures changes; that is, the transition from a solid-solid scheme to a solid-liquid scheme is observed. The strong influence of the heating rate on the reduction degree and kinetic parameters of the systems under study was affirmed. The simultaneous utilization of magnesium and carbon as reducers allowed the lowering of the starting and maximum temperatures of reduction processes, as evidenced by the synergetic effect at the utilization of a combined reducer. The effective values of activation energy (Ea) for the reactions proceeding in the mixtures NiO + WO3 + 4Mg, NiO + WO3 + 2.5Mg + 1.5C, NiWO4 + 4Mg and NiWO4 + 2Mg + 2C were estimated by Kissinger isoconversional method and were 146 ± 10, 141 ± 10, 216 ± 15 and 148 ± 15 kJ mol−1, respectively.

Preparation and Characterization of Novel Magnesium Composite/Walnut Shells-Derived Biochar for As and P Sorption from Aqueous Solutions

Elevated or unnatural levels of arsenic (As) and phosphorus (P) concentrations in soils and waterbodies from anthropogenic sources can present significant hazards for both natural ecosystems and human food production. Effective, environmentally friendly, and inexpensive materials, such as biochar, are needed to reduce mobility and bioavailability of As and P. While biochar features several physicochemical properties that make it an ideal contaminant sorbent, certain modifications such as mineral-impregnation can improve sorption efficiencies for targeted compounds. Here, we conducted sorption experiments to investigate and quantify the potential utility of magnesium (Mg) for improving biochar sorption efficiency of P and As. We synthesized a Mg-modified walnut shells-derived biochar and characterized its ability to remove As and P from aqueous solutions, thereby mitigating losses of valuable P when needed while, at the same time, immobilizing hazardous As in ecosystems. SEM-EDX, FTIR and elemental analysis showed morphological and functional changes of biochar and the formation of new Mg-based composites (MgO, MgOHCl) responsible for improved sorption potential capacity by 10 times for As and 20 times for P. Sorption efficiency was attributed to improved AEC, higher SSA, chemical forms of sorbates and new sorption site formations. Synthetized Mg-composite/walnut shell-derived biochar also removed &gt;90% of P from real samples of wastewater, indicating its potential suitability for contaminated waterbody remediation.

Evaluation of protein enriched co‐products originating from wheat fermentation in diets of common carp Cyprinus carpio to examine effects on growth response, mineral retention, haematological status and intestinal integrity

Six experimental isonitrogenous (380 g kg-1 crude protein) and isolipidic (80 g kg-1) diets were formulated for juvenile carp Cyprinus carpio. The fish meal protein component of a basal diet (control treatment) was effectively replaced by yeast protein concentrate unrefined (YPCU), yeast protein concentrate refined (YPCR), yeast protein concentrate potable alcohol (YPCPA) at 300 g kg-1 of total dietary protein originating from a novel wheat fermentation process. Distillers dried grains with solubles (DDGS) at two levels (150 and 300 g kg-1) of dietary protein were also tested separately. After an 8-week feeding trial, carp fed YPCU30 recorded the highest (p ≤ .05) growth performance and feed efficiency. The apparent net protein utilization of phosphorus, sodium, magnesium and chromium for all diets tested showed significant differences of retention efficiencies. The control fed carp had (p < .05) significantly lower phosphorus and magnesium efficiency than the carp fed other diets. Histological examinations showed the density of microvilli in the region of fish fed YPCU30, YPCPA30, DDGS15 and DDGS30 was decreased compared with the control fed fish with no significant differences were found among the treatments (p ≥ .05). Significant differences in the number of hepatocytes were observed between fish fed YPCR30 or YPCPA30 and DDGS30. Furthermore, no significant (p ≥ .05) differences were obtained in the number of hepatocytes in the fish fed YPCU30 and DDGS15 diets with fish fed the control diet. Hepatic structure showed that the liver of the fish fed the control, YPCU and YPCR diets appeared to be healthy with no signs of pathological change. In conclusion, fermented wheat-derived yeast protein concentrate and distillers dried grains with solubles are promising ingredients in carp diets to reduce feed costs and achieve aquaculture sustainability.

Metabolomics analysis reveals the responses of tea plants to excessive calcium.

The proper growth and development of tea plants requires moderately acidic soils and relatively low calcium levels, and excessive calcium at high pH can damage tea plant roots. To reveal the effects of calcium on the responses of tea plant to three pH levels (3.5, 5.0 and 6.5), a repeated test of two factors was designed. Root growth and elemental analysis indicated that excessive calcium improved the growth of tea roots at low pH conditions, whereas it did not harm the growth of tea roots under normal and high pH conditions, especially at pH6.5. Excessive calcium antagonized the absorption and utilization of magnesium by tea plants. Gas chromatography-mass spectrometry results showed that the addition of Ca2+ resulted in the primary metabolism in roots being more active at a low pH level. By contrast, it had obvious adverse effects on the accumulation of root metabolites with high calcium treatment at normal or high pH. Differential metabolites identified using ultra-performance liquid chromatography quadrupole time of flight mass spectrometry indicated that flavonoids demonstrated the largest number of changes, and their biosynthesis was partially enriched with excessive calcium at low and high pH conditions, whereas it was down-regulated under normal pH conditions. Kaempferol 3-(2'-rhamnosyl-6'-acetylgalactoside) 7-rhamnoside, quercetin 3-(6'-sinapoylsophorotrioside) and delphinidin 3-(3'-p-coumaroylglucoside) showed the greatest increase. The results of gene expression related to root growth and calcium regulation were consistent with root growth and root metabolism. The overall results demonstrated that high Ca concentrations further aggravate the detrimental effects of high pH to tea roots. However, it is interesting that excessive calcium reduced the harm of a low pH on tea root growth to some extent. © 2021 Society of Chemical Industry.

Modelling of the formulated solid rocket propellant characteristics

This study is a mathematical model to obtain the characteristics performance of magnesium metal (powder) and carbon on a potassium nitrate-sucrose (KNSU) solid propellant formulation. Characterization of propellant is, as a general rule, important to determine its performance before it can be suitable for use for a rocket flight or any mission. Method of ballistic load cell evaluation was used to validate results and a mathematical model using the combustion exhaust products was solved to obtain the characteristics performance parameters of the propellant. The carbon constituent which acts as an opacifier and coolant was kept constant at 2% in order to arrest some of the heat during the combustion process and helped to lower the combustion temperature, because high combustion temperature could lead to combustion chamber rupture or failure. The effect of addition of magnesium which was optimized for 3% in the formulation contributed significantly in improving the overall performance of the propellant. The utilization of magnesium in KNSU propellant provided higher values parameters and better performance compared to when not included. This was confirmed with the model equations. The propellant combustion products equation was used to model and obtain the characteristics performance parameters. This gave propellant specific impulse (122.9s), combustion temperature (1821K), heat ratio (1.1592), molecular weight (36.89g/mole), propellant density (1912.5kg/m3) and characteristics velocity (1000m/s) result while maintaining the same chamber pressure.

Utilization of Magnesium for the Treatment of Chronic Pain.

ContextThe International Association for the Study of Pain (IASP) defines chronic pain as pain that persists or recurs for longer than 3 months. Chronic pain has a significant global disease burden with profound effects on health, quality of life, and socioeconomic costs.Evidence AcquisitionNarrative review.ResultsThere are several treatment options, including pharmacological therapy, physical rehabilitation, psychological therapies, and surgical interventions, for chronic pain management. Magnesium has been FDA-approved for several indications including hypomagnesemia, arrhythmia, prevention of seizures in eclampsia/preeclampsia, and constipation. Magnesium has been used for numerous off-label uses, notably for acute and chronic pain management. The mechanism of magnesium in pain management is primarily through its action as a voltage-gated antagonist of NMDA receptors, which are involved in pain transduction.ConclusionsThis narrative review will focus on the current evidence and data surrounding the utilization of magnesium as a treatment option for chronic pain.

Manipulating Phosphorus, Calcium, and Magnesium Utilization by Growing Lambs Using Natural Zeolite (Clinoptilolite)

A total of 24 three-month-old lambs with an average weight of 23 ± 1.5 kg were used in this study and fed a complete diet supplemented with natural zeolite at 1% and 2% of feed weight to evaluate the effect of zeolite on calcium (Ca), phosphorus (P), and magnesium (Mg) concentration in tissues (kidney, liver, and muscle), rumen fluid, and blood. Adding zeolite at 2% to the diet resulted in an increase (p &lt; 0.05) in body weight but a depressed feed conversion ratio. Phosphorus digestibility was significantly (p &lt; 0.05) increased with the addition of zeolite while the digestibility of Ca and Mg remained unaffected (p &gt; 0.05). The concentration of Ca, Mg, and P in the liver remained unchanged (p &gt; 0.05) with the addition of zeolite. The addition of zeolite led to a decrease (p &lt; 0.05) in the Ca concentration in the kidney and muscle, whereas the Ca concentration in lambs receiving diets supplemented with 2% zeolite (123.13 and 48.49 µg/g) was significantly (p &lt; 0.05) higher than supplementation at 1% (120.13 and 45.66 µg/g, respectively, for kidney and muscle). Furthermore, serum and rumen fluid concentrations of P, Ca, and Mg exhibited no significant differences upon the addition of zeolite to the diet. Conclusively, diet supplementation by zeolite at 2% improves performance and especially P digestibility, which may result in the reduction in minerals in lambs’ waste and consequently a reduction in environmental pollution.

Extraction of magnesium from garnierite by carbothermal reduction in vacuum

The aim of the traditional pyrometallurgical processes is to extract nickel and iron in garnierite, but it is difficult to extract magnesium of higher value in minerals. Aimed at solving this problem, the extraction of magnesium from garnierite is proposed and studied in this study. The effects of different reduction temperatures, different reduction times and dosage of CaO additions in experiments were investigated. The experimental results indicate that the extraction rate of magnesium can reach 93.23% when the mass ratio of mineral/reductant is 100:28.3, system pressure is 50 Pa, reduction temperature is 1823 K, and reduction time is 120 min, and, at the same time, the purity of metal magnesium in the condensate can be up to 91.88%. Under these conditions, the extraction rate of magnesium can increase to 99.45% by adding 25 wt% CaO, and the purity of the metal magnesium in the condensate exceeds 90%. CaO as the additive can effectively improve the extraction rate of magnesium and promote the recovery and utilization of magnesium. The mechanism is that CaO replaces –O–Mg– in the –O–Mg−O–Si−O– structure to form free MgO, which is reduced to Mg vapor by carbon and condensed into magnesium metal in the condensation zone to achieve the purpose of removing and collecting Mg from the garnierite. At the same time, the reduced slag is rich in Ni and Fe, which can be used for the extraction of Ni and Fe. Compared with the traditional pyrometallurgical process, the process can extract magnesium from garnierite, and the process is short and its operation is simple, which is a potential technology.

Risk variables associated with abnormal calcium, magnesium and phosphate levels among emergency department patients.

The utility of calcium, magnesium and phosphate measurement in the ED is limited. We aimed to determine clinical risk variables for abnormal levels of these electrolytes in order to inform the development of an ordering guideline. We performed a retrospective, observational study of patients who presented to a tertiary referral ED between January and June 2017. Adult patients who had serum calcium, magnesium or phosphate tests completed during their ED stay were included. Presenting symptoms and signs, comorbidities, medication use and laboratory values were extracted from the medical record. Patients with missing data items were excluded. Logistic regression models determined clinical risk variables associated with low and high levels of each electrolyte. A total of 33 120 adults presented during the study period. Of the 1679 calcium, 1576 magnesium and 1511 phosphate tests, 228 (13.6%), 158 (10.0%) and 387 (25.6%) were abnormal, respectively. Significant risk variables (P < 0.05) for abnormal levels were: hypocalcaemia - vomiting, perioral numbness, hand/foot spasm, calcium and phosphate supplements and chemotherapy (odds ratio [OR] range 5.9-17.3); hypercalcaemia - female sex, vomiting, polyuria, confusion, hyperparathyroidism, cancer and type 1 diabetes (OR range 2.3-9.7); hypomagnesemia - female sex, proton pump inhibitor use, tacrolimus use, alcohol abuse and type 2 diabetes (OR range 2.2-13.1); hypermagnesemia - lethargy, thiazide use and chronic kidney disease (OR range 4.3-4.5); hypophosphatemia - nausea, seizure and glucocorticoid use (OR range 1.7-2.1); and hyperphosphataemia - polyuria, diuretics and chronic kidney disease (OR range 1.9-5.0). A range of demographic, comorbid, medication and clinical variables are associated with abnormal calcium, magnesium and phosphate levels. These findings will inform the development of clinical guidelines to rationalise calcium, magnesium and phosphate testing. Justification may be required for testing patients with no risk variables.