Comparative study of oxide inclusion dissolution in CaO-SiO2-Al2O3 slag

The dissolution of alumina, spinel and zirconia inclusions in a liquid CaO–SiO2–Al2O3 slag has been investigated using laser scanning confocal microscopy. Over the experimental temperature range 1477–1577uC it is found that alumina inclusions have a slower dissolution rate than that of spinel, and that zirconia inclusions form gas bubbles at the inclusion surface during dissolution. The results have been analysed assuming mass transfer control in the slag phase, and the slower rate of dissolution of the alumina inclusions is explained by the observation that they have a greater mass of aluminium oxide, the rate controlling species, than that of spinel

The effect of calcium aluminates on the coke analogue gasification

The gasification rate in CO2 of the coke analogue containing calcium oxide was studied using analogues doped with alumina (corundum), calcium aluminates (CA6, CA, C3A) and lime minerals. The coke analogue is a laboratory material with simplified carbon structure that has a mineral component with a particle size, size distribution and mineral dispersion that can be controlled. The main focus of this study was to quantitatively assess the effect of calcium in the mineral on the analogue’s reactivity. The analogues were reacted with CO2 isothermally in the temperature range of 1173–1623 K. It was found that the reaction rate increased with increasing CaO activity/number of moles of Ca in the mineral. The relative reaction rates (from lowest to highest) of the analogues doped were alumina, CA6, CA, C3A and lime. The relative apparent activation energies of the gasification from lowest to highest was lime, C3A, CA, CA6 and alumina

The effect of slag basicity on spinal inclusion wettability

Steel cleanness is an important and growing research area driven by the demands to produce high quality steel. Inclusion content in steel is an important criterion to assess clean steel. MgO.Ah03 spinel inclusions cause problems in steel processing and are generally deleterious to steel products due to their high melting point and high hardness. Jnclusions are generally r· moved by rea ting with slag. This is primarily achieved by optimizing lhe PI\u27 \u27ess omliLions to promote contact and reaction between the inclusion and S,l,lg \u27. or efticient rem val from the steel the inclusions must attach to and dissolve in the slag pba~e. If this atta hment is weak, then local fluid conditions are likely to result in the shearing of this attachment and the inclusions re-cntrapment in the . tee!. The strength of attachment (reactivity) between the inclusion and tJle slag phase can be characteri zed by the wettability of the slag on inclusions 2-3. Research on inclusion removal in steel refining is principally divided into categories of flotation of juclusion Lo the steel/slag interi\u27ace 4-5 modification to improve reactivity/separation wilh the sJag phase (j and dissoluti n in lhe s lag phase

The evaluation of tuyere coke probing data at Bluescope Steel Port Kembla Works

Tuyere coke probings have been conducted at Port Kembla over the past decade. This period of operation spans significant change in coking coal preparation as well as the introduction of pulverised coal injection

Behaviour of New Zealand ironsand during iron ore sintering

Titanium-bearing burdens are commonly introduced into blast furnaces to protect the hearlh because the so-called titanium bear which is a precipitate of carbide, nitride and carbonitride of titanium may form in the blast furnace hearth if Ti02 is present in the feed [1 , 2J. New Zealand ironsand is a titanomagnetite, containing around 60 wt.% iron, 8 wt.% titanium and other substances such as silica, phosphorus and lime [3, 4]. Since it is competitive in price, introduction of the ironsand into the ferrous feed can reduce the production cost and potentially increase blast furnace campaign life. An appropriate method of inlroduction of ironsand is as a component of the sinter as the small size of ironsand precludes direct charging into the blast furnace. Although the effect of introducing titanomagnetite into iron ore blends has been investigated [1,,2, §],little is known about the detailed sintering mechanism. The present study is aimed at identifying the sintering behaviour of New Zealand ironsand as well as the interaction between New Zealand ironsand and CaO to gain better understanding of sintering mechanism of titanomagnetite

Sintering of Iron Ores in a Millipot in Comparison with Tablet Testing and Industrial Process

To explore the feasibility of small-scale sintering pot testing, a \u27millipot\u27 facility (diameter of 53 mm and height of 400 mm) was established and used to examine the sintering performance of iron ores and other non-traditional ferrous materials. The sintering performance of a millipot was examined across a range of different operational conditions (coke rate and suction pressure) and compared with an industrial sinter strand operation. Tablet tests were also performed to assist in the design of the millipot experiments and identify conditions for achieving mineral composition similar to the industrial sinter. For the millipot experiments, the materials used need to be compacted to increase the bulk density, and a higher coke rate is required to compensate the high heat loss caused by wall effects. A higher suction pressure is also necessary to maintain an oxidizing atmosphere in the sinter bed. As expected, it was not possible to eliminate the wall effect, which resulted in more primary hematite at edges of the sintered column. However, the sintered material from the center of column simulates industrial sinter reasonably well. As such, millipot provides a practical way to evaluate the sintering process and material performance at laboratory scale, helping to bridge the gap between tablet sintering and large scale pot sintering, or full scale plant trial. The results of millipot testing can be used for designing larger scale experiments or commercial sintering trials

A Needs Assessment for Simulation-Based Training of Emergency Medical Providers in Nebraska, USA

Background: Training emergency medical services (EMS) workforce is challenging in rural and remote settings. Moreover, critical access hospitals (CAHs) struggle to ensure continuing medical education for their emergency department (ED) staff. This project collected information from EMS and ED providers across Nebraska to identify gaps in their skills, knowledge, and abilities and thus inform curriculum development for the mobile simulation-based training program. Methods: The needs assessment used a three-step process: (1) four facilitated focus group sessions were conducted in distinct geographical locations across Nebraska to identify participants\u27 perceived training gaps; (2) based on the findings from the focus group, a needs assessment survey was constructed and sent to all EMS and ED staff in Nebraska; and (3) 1395 surveys were completed and analyzed. Results: Thematic areas of training gaps included cardiopulmonary conditions, diabetes management, mass casualty incidents (MCI), maternal health and child delivery, patient assessment, pediatric care (PC), and respiratory emergency care. Gaps in non-clinical skills were related to crisis management such as maintaining effective teamwork. Participants frequently identified cardiopulmonary care, PC, and MCI as highly needed trainings. Other needs included life support-related retaining courses, sessions informing protocol updates, the availability of retraining tailored for rural areas, substance use-related emergencies, and farming-related injuries. Conclusion: EMS and ED staff identified several skill gaps and training needs in the provision of emergency services in rural communities. These results allow for the development of customized training curricula and, with the help of an on-site simulation-based program, can identify gaps in health professionals\u27 skills, knowledge, and abilities and thus help them respond to acute healthcare needs of rural communities

Erratum to: Methods for evaluating medical tests and biomarkers

[This corrects the article DOI: 10.1186/s41512-016-0001-y.]