Metallurgical processing of converter slag

Converter slurries at modern metallurgical plants represent a significant part of metal-containing industrial waste with a high concentration of iron. Currently, there is a problem of their utilization and use as raw materials for metallurgy. The purpose of this work is to study the processes of briquetting and recovery of briquetted products, based on a mixture of converter slurries of gas purification and converter slags. When performing experimental studies on the preparation of sludge briquettes from a mixture of converter sludge of gas purification and converter slag, their metallization and reduction melting in laboratory conditions, the optimal composition of the components of the mixture of converter slag and gas purification sludge was determined by the percentage of iron, which is appropriate for use as a raw material for steel smelting. Experimental studies on the preparation of sludge-coal mixtures from dispersed metal-containing and carbon-containing industrial waste with stoichiometric coal consumption for the recovery of extracted metals have proved the possibility of obtaining sludge-coal briquettes, which are further subjected to metallization and reduction melting. Sequential processing of dispersed production waste, namely drying, metallization and reduction melting, allowed us to obtain at the final stage a metal sample that corresponds to high-quality steel in its composition. Based on the analysis of the results of experimental studies, the technology of reducing melting of metal-containing waste has been developed. As a result of the implementation of the technology, high-quality steels and alloys can be obtained without carburizing the metal, bypassing the production stages of cast iron and high-carbon alloys. The content of harmful impurities of sulfur and phosphorus meets the technical requirements of high-quality steel. The proposed technology for processing slag and sludge from oxygen-converter production will reduce the volume of accumulated production waste.

Analysis of the Root Causes of Damage to the Edges of Tank Manholes on the Main Deck of Handy-Size Bulk Carriers

This study analyzes the root causes of cracks in the deck plating around tank manholes. Four handy-size bulk carriers built in one shipyard were analyzed. In all cases, deck cracks were found near manholes, and the average time from the commencement of operation until the occurrence of cracks was 1356 days. Due to this short wear-life of the vessel’s structural material, the authors believed that it was unlikely to be caused by corrosion fatigue. The authors hypothesized that main decks cracked around manholes because of very poor-quality welded joints and poor-quality steel (large amounts of non-metallic impurities) used to make the manholes. In order to verify this hypothesis, on each of the vessels, material samples were collected from near the cracks and then examined thoroughly. Each sample was subjected to the macroscopic examination of the natural surfaces of cracks and their vicinity, microscopic examination of the material, mechanical property tests, and scanning electron microscope fractography for samples obtained after impact tests. The examination and test results were used to draw detailed conclusions for each case study. The general conclusions based on examination of the whole damage population validated the authors’ hypothesis that main decks cracked around manholes because of very poor-quality welded joints and poor-quality steel used to make the manholes.

Uji Kuat Lentur Profil Baja Ringan Galvalum Tipe C yang Di Grouting Dengan Variasi Mortar

Cold form steel is one type of material that is currently experiencing very rapid development. The advantages of the using cold form steel are so many, one of which is the light weight and high quality steel. This is an added value for cold form steel. But one of the weakness in cold form steel profile is the buckling effect. So that additional fillers are needed so that cold form steel has resistance with buckling effect. Mortar is a filler that is often used in construction. Therefore this research will be discuss the analysis of grouting mortar to prevent buckling effect in the cold form steel profile. And then the grouting mortar that will be used uses a variation of cement to sand as big as 1:1, 1:2, 1:3 and 1:4. From the results of the compressive strength of the mortar obtained compressive strength of 1: 1 has the greatest compressive strength of 30 Mpa. And then for the flexural test, the steel beam with mortar variation 1: 1 has the greatest resistance of 9558 Newton, with the smallest deflection value of 8 mm and the greatest stress of 19.47 Mpa, when compared to steel beams with variations of 1: 2, 1: 3, 1: 4 and steel beams without fillers.