Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

Microwave dephosphorisation of high phosphorus iron ores of the Aswan region, Egypt:developing a novel process for high phosphorus iron ore utilization

Abstract There is a rapidly increasing demand for iron resources with the fast-paced development of the iron and steel industry. For this reason, the iron and steel industry is facing the risk of a raw material shortage. Deposits of high-phosphorus iron ores are widely spread worldwide, but the use of these deposits in industry is limited owing to the high phosphorus content, which affects the cost of the iron making process and the quality of the produced steel. For the utilization of high phosphorus oolitic iron ore, many hydrometallurgical and pyrometallurgical processes have been proposed. However, these methods have disadvantages, such as causing environmental pollution, not being cost-effective, being overly time consuming and having low iron recovery. The aims of this present work are to study the possibility of the usage of microwave treatment to remove phosphorus from high phosphorus iron ore on a laboratory scale. This objective can be obtained through a combination of microwave pretreatment and physical separation methods. The findings into the microwave treatment of high phosphorus iron ore are quite promising. The results have indicated that microwave heating increase liberation, improves magnetic properties and reduces the processing time of iron ore. The results of ultrasound treatment showed that a significant increase in iron grade and a reduction in phosphorus content of the product can be obtained. The results indicate that microwave pretreatment should be considered as a factor significantly affecting the result of ultrasonic treatment. Depending on the sample texture and degree of phosphorus liberation, more than 59 % phosphorus removal can be obtained.Tiivistelmä Raudan ja teräksen valmistusmäärien kasvaessa on tarve jalostaa aiemmin hyödyntämättömiä rautamalmeja ja ehkäistä siten mahdollinen raaka-ainepula tulevaisuudessa. Maailmalla on runsaasti rautamalmiesiintymiä, jotka sisältävät paljon fosforia. Näitä esiintymiä käytetään suuren fosforipitoisuuden vuoksi vain rajallisesti, koska fosfori heikentää raudan valmistusprosessin kustannustehokkuutta ja tuotetun teräksen laatua. Paljon fosforia sisältävän ooliittisen rautamalmin hyödyntämiseksi on ehdotettu monia erilaisia hydro- ja pyrometallurgisia prosesseja. Näihin menetelmiin liittyy kuitenkin haittapuolia, kuten huomattava ympäristörasitus, heikko kustannustehokkuus, prosessien hitaus ja alhainen raudan talteensaanti. Tämän tutkimuksen tavoitteena oli tutkia laboratorio-olosuhteissa mahdollisuutta käyttää mikroaaltokäsittelyä fosforin poistamiseen paljon fosforia sisältävästä rautamalmista. Fosforinpoistoa tutkittiin mikroaaltoesikäsittelyn ja mekaanisten erottamisprosessien avulla. Tutkimuksen perusteella mikroaaltokäsittely vaikuttaa olevan lupaava tapa poistaa fosforia paljon fosforia sisältävästä rautamalmista. Tutkimustulosten mukaan mikroaaltolämmitys parantaa erotustehokkuutta ja magneettisia ominaisuuksia sekä vähentää rautamalmin käsittelyyn kuluvaa aikaa. Ultraäänikäsittelyn tulokset osoittavat, että prosessin avulla voidaan parantaa merkittävästi rautarikasteen laatua ja pienentää rikastetuotteen fosforipitoisuutta. Tulokset viittaavat siihen, että mikroaaltoesikäsittelyllä voidaan merkittävästi vaikuttaa ultraäänikäsittelyn tehokkuuteen. Malmipartikkelien tekstuurista ja fosforin erottamisasteesta riippuen tutkitulla menetelmällä voidaan poistaa jopa 59 prosenttia fosforista

Effect of steelmaking dust characteristics on suitable recycling process determining:ferrochrome converter (CRC) and electric arc furnace (EAF) dusts

Abstract Utilization of dusts generated from steelmaking industries will avoid disposal of wastes, enhance the use of secondary raw material fines and save costs. Understanding the properties of dust is necessary before determining the suitable recycling method. The present paper describes the chemical, morphological and mineralogical characterization of steelmaking dusts produced in steel plants in Finland. In this paper three different steelmaking dusts: ferrochrome converter (CRC) and electric arc furnace stainless steel (EAFSS) dusts from Outokumpu (Tornio, Finland), and electric arc furnace carbon steel (EAFCS) dust from Ovako (Imatra, Finland) were characterized. The characterization study showed that, the dusts from carbon steelmaking (EAFCS) are rich in zinc, while the dusts from stainless steelmaking (CRC) and (EAFSS) are relatively low in zinc, but richer in chromium. The zinc contents in CRC, EAFSS and EAFCS dusts are 10.83, 19.84 and 35.76 wt%, respectively, while the chromium contents are 20.88, 3.19 and 0.47 wt%, respectively. In the dust from CRC, zinc is found as zinc oxide (zincite, ZnO), while in the dusts from EAFSS & EAFCS zinc is found mostly as zinc ferrite (franklinite, ZnFe₂O₄). Scanning electron microscopy (SEM) investigations indicated that CRC dust is dominated by non-spherical form and composed mainly of aggregates of irregular particles of chromite, in addition to zincite sphere. EAFSS dust particles are characterized by encapsulation phenomenon, franklinite particles enclosed inside calcium-iron-silicate glass sphere. Manganese (Mn) concentrations show positive correlation with Zn, which suggests the occurrence of Mn mainly with franklinite phase. EAFCS dust is dominated by spherical form, and zinc found as franklinite and zincite. In the large particles > 3 μm of EAFCS dust, franklinite enclosed inside glass sphere, while in finer particles < 1 μm, both zincite and franklinite existed as spheres. The investigations indicate that steelmaking dusts from CRC, EAFSS, and EAFCS show significant difference in concentration and mode of occurrence of zinc in the dusts, which will influence the determination of suitable processing methods

Recovery of metals and rare earth elements by microwave heating technology:a review

Abstract Microwave heating technology is considered one of the most likely to replace traditional heating methods due to its efficient, quick, and green heating transmission that meets the requirements of sustainable development. Microwave heating can strengthen chemical reactions and change the morphology of minerals, and it can save energy and achieve rapid and efficient heating, clean production, and emission reduction. Therefore, this paper summarizes the research status of microwave heating in the recovery of valuable metals (Cu, Au, V),) from metallurgical waste ore and rare earth elements from rare earth minerals in recent years, expounds the principle of microwave heating, and summarizes the previous experimental phenomena. Finally, the development potential, opportunities, and difficulties of microwave technology in future industrial applications are discussed

Effect of blast furnace sludge (BFS) characteristics on suitable recycling process determining

Abstract The present study aims to give a detailed characterization of blast furnace sludge (BFS) by using different techniques, in order to determine the most effective recycling method to recover valuable metals from this waste. BFS is composed mainly of hematite, as its iron-bearing phase, and carbon, in addition to fractions of silicate and carbonate materials. The studied BFS shows relatively high contents of iron (Fe) (390 g.kg-1), and carbon (C) (290 g.kg-1), due to abundance of hematite and coke, while the concentration of zinc (Zn) (2.5 g.kg-1) is low. The XRD analyses indicated that, hematite is more concentrated in the fine fraction (<20 μm), while the coarser fraction (90 - 250 μm) is dominated by calcite, quartz and X-ray amorphous coke. SEM-EDX analyses confirmed that particles rich in iron and zinc were detected in the fine fraction (<20 μm) of the sludge. Due to high Fe and C content in BFS, it can be utilized as self-reducing material and briquetting represent a potential method for recycling of blast furnace sludge

Selective zinc removal from electric arc furnace (EAF) dust by using microwave heating

Abstract Recycling of electric arc furnace (EAF) dust helps to avoid disposal of wastes, conserves resources, and minimizes its environmental impact. This study aimed to investigate the selective zinc removal from EAF dust by means of microwave heating oven as a heat source. The effect of microwave heating temperature on the selective zinc removal from EAF dust was studied at temperatures of 750 °C, 850 °C, and 950 °C. The mixture of EAF dust and graphite was well homogenized and compressed to pellet and heated for 20 min at the microwave power of 1.1 kW. X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM–EDS) techniques were used to characterize the residue after microwave treatment. The results indicated that the reduction and the recovery of zinc increase with the rising temperatures. The temperature of 750 °C was insufficient for the volatilization of zinc. Zinc removal of 94% was achieved after microwave heating at 950 °C. The residue that remained in the crucible was composed mainly of metallic iron and calcium ferrite. These results indicated that a temperature of 950 °C is suitable for selective removal of zinc from EAF dust, which is in accordance with the thermodynamic calculations

Enhanced Leaching of Zinc from Zinc-Containing Metallurgical Residues via Microwave Calcium Activation Pretreatment

Given the shortage of zinc resource, the low utilisation efficiency of secondary zinc resource, and the crucial problem that the synchronous dissolution of zinc from different mineral phases, an activation pretreatment method merged with calcium activation and microwave heating approach was proposed to enhance the zinc leaching from complex encapsulated zinc-containing metallurgical residues (ZMR). Results indicated that under the optimal pretreatment conditions, including microwave activation temperature of 400 °C, CaO addition of 25% and activation time of 20 min, the zinc leaching rate reached 91.67%, which was 3.9% higher than that by conventional roasting pretreatment. Meanwhile, microwave heating presents excellent treatment effects, manifested by the zinc leaching rates, all exceeding that of conventional roasting under the same conditions, while the process temperature is decreased by 200 °C. In addition, XRD and SEM-EDS analysis denoted that microwave calcification pretreatment can effectively promote the transformation of the refractory zinc minerals like Zn2SiO4 and ZnFe2O4 into the easily leachable zinc oxides. The distinctive selective heating characteristics of microwave heating strengthened the dissociation of mineral inclusion, and the generated cracks increased the interfacial reaction area and further enhancing the leaching reaction of zinc from ZMR

Investigations on the Thermodynamics Characteristics, Thermal and Dielectric Properties of Calcium-Activated Zinc-Containing Metallurgical Residues

An activate pretreatment of zinc-containing metallurgical residues were proposed by adding CaO and introducing microwave heating approach into the CaO activation pretreatment process to realize the conversion of refractory ore phases into pre-treated ore phase. Thermodynamic characteristics analysis indicated that adding CaO can realize the conversion of refractory ore phases, with the same effect as the carbon additives. Thermal conductivity properties analysis denoted that the thermal conductivity properties of ZnS and ZnFe2O4 were relatively poor. Meanwhile, the thermal conductivity properties of the residues sample added with 25% CaO were significantly superior to the residues added with other CaO contents, with the maximum specific heat value of 1.348 J/g·K at 350 °C. Dielectric properties analysis highlighted that adding CaO with the dielectric constant properties significantly higher than that of other substances can enhance the microwave absorption capacity of zinc-containing residues. The decrease in dielectric loss and loss tangent value with the increase of temperature and the residues having large microwave penetration depth guaranteed to obtain better uniformity of microwave heating. Furthermore, adding 25% CaO promoted the microwave penetration depth of the residues sample increased in the range of 300–500 °C. This work can lay a theoretical research foundation for solving the key difficulty for efficient Zn recovery from complex zinc-containing metallurgical residues

Thermal and mass spectroscopic analysis of BF and BOF sludges:study of their behavior under air and inert atmosphere

Abstract Differential thermal analysis (DTA), thermogravimetry (TG), and mass spectrometry (MS) were used to study the thermal behavior of the blast furnace (BF) and basic oxygen furnace (BOF) sludges generated from the iron-making industry. The results indicated that under air atmosphere the two types of sludge are different in their thermal behavior. In BF sludge, the exothermic carbon gasification (CO/CO₂) reaction dominated the process, while in BOF sludge, the significant reaction occurred at 755 °C and was associated with a slight mass gain owing to the partial oxidation of Fe₃O₄ to Fe₂O₃. Under inert atmosphere, the thermal behavior of both BF and BOF sludges were dominated by a reduction reaction. In BF sludge, the endothermic reactions ranged from 785 to 1115 °C due to the reduction of iron oxides as follows: Fe₂O₃ → Fe₃O₄ → FeO → Fe. A total mass loss of about 27.78% was observed in the TG curve. While in BOF sludge, the endothermic peaks corresponded to magnetite reduction to iron (Fe). The overall mass loss of the BOF was approximately 16.92%. The mass spectrum of gases evolution for both BF and BOF sludges revealed that CO/CO₂ gases were released from the sludges