Jun-Hyung Seo

요 약 본 연구는 다양한 산업부산물을 활용하여 고강도 클링커를 제조하기 위해 원료 배합 설계 및 이에 따른 클링커 주요 광물상(C3S, C2S, C3A, C4AF)의 형성 특성을 분석하였다. 실험을 통해 원료 대체율 및 Modulus 조건(LSF, SM, IM)이 클링커의 주요 광물상의 형성과 물 리적 특성에 미치는 영향을 확인하였다. 소성온도 1,500 ℃, LSF 100, SM 2.7, IM 1.5의 Modulus 조건에서 제조된 A-1 클링커는 C3S 생 성량이 75.0 %으로 확인되었으며

In an effort to achieve the goal of carbon neutrality, countries around the world are aiming to phase out coal-fired power plants. Due to various reasons, electricity production through coal-fired power generation and sulfur oxide (SOx) emissions are expected to continue in the future. In the South Korea, sodium bicarbonate (NaHCO 3) and lime materials are used to treat SOx, and most of the sodium bicarbonate is imported. Therefore, this research was conducted to replace sodium bicarbonate by improving the physical properties of lime materials using domestic limestone. Limestone was heat-treated through a box-type electric furnace and a vertical electric furnace. Due to the structural characteristics of the vertical electric furnace, a lime material(quicklime) was possible to improve the physical properties like a specific surface area and a pore volume. Then, they were reached to 22.33 m 2 /g specific area and 0.14 cc/g pore volume.

Titanium's importance as a mineral resource is increasing, but the Korean industry depends on imports. Ilmenite is the principal titanium ore. However, research and development from raw materials have not been investigated yet in detail. Hence, measures to secure a stable titanium supply chain are urgently needed. Accordingly, through beneficiation technology, we evaluated the possibility of technological application for the efficient recovery of valuable minerals. As a result of the experiments, we confirmed that mineral particles existed as fine particles due to weathering, making recovery through classification difficult. Consequently, applying beneficiation technologies, i.e., specific gravity separation, magnetic separation, and flotation, makes it possible to recover valuable minerals such as hematite and rutile. However, there are limitations in

The lime industry accounts for about 75% of greenhouse gases generated from process emissions, and because large amounts of fossil fuels are used, the intensity of greenhouse gas emissions per unit of product production is quite high. In order to respond more accurately and quickly to greenhouse gas regulations, including the domestic emissions trading system, it is necessary to establish a system for accurately identifying greenhouse gas emission sources and calculating emissions for each lime manufacturing process. In this study, in order for limestone processing companies to effectively respond to the domestic greenhouse gas emissions trading system, the operation method, input raw materials, and fuel differences for each type of limestone kiln were identified through field surveys, and the greenhouse gas emission intensity was analyzed As a results, it was confirmed that greenhouse gas emissions were reduced when using a Parallel flow regenerative kiln compared to an improved shaft kiln even when the same amount of limestone was used.

In this study, soda lime was prepared from slaked lime to expand the scope of limestone use. To evaluate carbon dioxide absorption, an extruder-type and disc-type pelletizers were used to make the soda lime using bentonite as an additive. Regardless of the pelletizing process, the peak of CaCO 3 was confirmed in soda lime due to its reaction with carbon dioxide. Furthermore, it was confirmed that both calcite and aragonite were present together. The soda lime prepared using the disc-type pelletizer showed a larger specific surface area than that prepared using the extruder-type pelletizer did, and the specific surface area improved on adding bentonite. The carbon dioxide absorption rate increased under the sample condition with an enhanced specific surface area.

Domestic limestone industries need to prepare for the introduction of a paid allocation according to The 4th emission trading system. The limestone industry must reduce its greenhouse gas (GHG) emissions through process improvements (such as fuel conversion and increase in kiln efficiency) and system improvements (such as reflecting purity of raw materials and lime kiln dust factors). In addition, the limestone industry is currently classified within the same category as the cement industry. Therefore, when allocating emission allowances for greenhouse gas, it is possible that a low adjustment factor will be applied for the limestone industry due to differences in the industrial scale, raw materials, and product characteristics. The limestone and cement industries should thus be classified as two separate industries. Since unslaked lime and light-burnt dolomite are essential materials in a number of domestic industries, governmental support is essential to become a carbon-neutral and sustainable industry.

The cement industry, which is an energy-intensive and high carbon dioxide emission industry, requires strategy for carbon neutrality and sustainable development. Most domestic cement companies are generating electricity by waste heat recovery system to improve energy efficiency during cement processes; however, few studies exist on recycling of energy related to this. Certain countries with high cement production researched on modifying the conventional waste heat recovery system to maximize waste heat recovery using various methods such as applying the Rankine cycle depending on the temperature, comparing working fluids, applying two or more Rankine cycles, and combining with other industries. In this study, we reviewed the research direction for energy efficiency improvement by summarizing waste heat recovery and utilization methods in the domestic and overseas cement industries.