Optimal Replacement of Granite Modified with Ife Iron and Steel Slag on Strength Properties of Concrete

Steel is produced from iron ore and purification of metal scrap, leading to manufacture of hundreds of tonnes of steel slag each year. This study investigated the optimum replacement of granite with Ife Iron and Steel Nigeria Limited (ISN) slag that produce maximum Compressive Strength (CS), Split Tensile Strength (STS) and Flexural Strength (FS) of concrete using Response Surface Methodology (RSM) from Design Expert Version 7.0. The outcome of the study showed that the optimum replacement of granite with ISN was 28.85% ISN at 0.47 W/C.

Unraveling the interactions of reductants and reaction path over Cu-zeolite for coal-gas- via transient reaction study

with coal gas can be a solution for NOx emission control in iron and steel industry, nevertheless the coal-gas- is not clearly understood and hard to study due to the...

Justification for using resourcesaving banding technology in renovative production

The article substantiates the expediency of applying the basics of resource saving in the development of innovative technologies for strengthening serial parts and restoring worn ones. At the same time, the main task is the rational use of available material resources in the conditions of a decline in production, when it becomes profitable to restore metal-intensive parts worn out to a critical level. In capital repair of machines, the main problems are associated with the energy intensity of the process and a significant number of rejected parts that cannot be restored. Currently, most of the worn-out metal-intensive cast iron and steel body parts that have exhausted the resource are subjected to energy-intensive melting. For the reuse of metal-consuming parts in operation, a technology has been proposed for multilayer banding of a worn surface, in which steel tape is used instead of traditional banding rings. Winding the tape occurs under an interference in several layers. In this case, a multilayer bandage with interturn stresses is formed, which is not inferior in strength to a whole banding ring. The use of a steel “bandage” for the “treatment” of parts reduces the metal consumption for its manufacture by 2.5 times in comparison with the well-known one-piece ring made of round steel. As an example, the article substantiates the possibility of carrying out the banding process in relation to the restoration and strengthening of the seat under the bearing of the housing part. A multilayer bandage can also be used in the recovery of metal-intensive rolling rolls written off in scrap used on broadband cold rolling mills.

New Efficient Configurations for Sour Wastewater Treatment-

Background: Due to the technological development, the environmental legislations on pollutant concentrations in aqueous effluents tend to tighten and increase. As a result, sour water must be handled and processed properly to provide a high quality of stripped water with insignificant traces of NH3 and H2S in it. This must be achieved within the minimum operating costs. This research investigates the stripping configurations of sour water effluents from various industries. The research also offers an insight on different scenarios and configurations to accomplish set targets satisfying the environmental law criteria. Methods: This research introduces a range of heat integration schemes for better energy savings, further vapor recompression VRC technique is opted for its ability to maximize energy savings. This research analyses the effect of operating and design variables on the stripped water quality such as feed temperature, feed location, reflux split, and steam flow rate. The option of adding new equipment is also addressed to maximize heat integration and enhance the efficiency of the process. Thus, several schemes and process configurations are explored to treat industrial sour water waste streams seeking better efficiency. These configurations differ from one another in heat integration layout and whether VRC is utilized or not. Energy efficiency and economics of the proposed configurations are considered as decisive factors in this research study. The case study adopted are based on published data taken from some iron and steel factories in South Korea named POSCO (Pohang Iron and Steel Corporation). Results: Results of the treated wastewater streams guarantee that the effluent sour water obeys standard environmental regulations, i.e., NH3 contents range from 30 to 80 ppm and H2S concentration falls below 0.1 ppm. The obtained results of the seven different scenarios are compared to the original case study. It is found that scenario 7 is the most economical solution saving 51.54 % in total annual cost when compared to the original case study, while satisfying the treated water environmental regulations with a concentration of 3.19 ppm NH3 and 0.05 ppm H2S. Scenario 7 creates its own steam unlike the original case study where steam utility is needed extensively. However, scenario 7 consumes 15 % more electricity than the original case study but still shows 56.34 % less utility cost in overall. Conclusion: The optimum process configuration can be employed for other sour water purification systems such as those from petroleum refiners. An ongoing research work is focusing on the use of internal heat integration for more energy savings and economics improvement.