The combination of multiple classifiers, commonly referred to as a classifier ensemble, has previously demonstrated the ability to improve classification accuracy in many application domains. As a result this area has attracted significant amount of research in recent years. The aim of this paper has therefore been to provide a state of the art review of the most well-known ensemble techniques with the main focus on bagging, boosting and stacking and to trace the recent attempts, which have been made to improve their performance. Within this paper, we present and compare an updated view on the different modifications of these techniques, which have specifically aimed to address some of the drawbacks of these methods namely the low diversity problem in bagging or the over-fitting problem in boosting. In addition, we provide a review of different ensemble selection methods based on both static and dynamic approaches. We present some new directions which have been adopted in the area of classifier ensembles from a range of recently published studies. In order to provide a deeper insight into the ensembles themselves a range of existing theoretical studies have been reviewed in the paper.

In the general frame of energy saving, environment protection and the concept of circular economy, the fundamental research on the sintering technology with super deep bed, achieving energy saving and emission reduction, was carried out. At first, the characteristics of the process and exhaust emission in the sintering with super deep bed was mastered through the study of the influence of different bed depths on the sintering process. Then, considering the bed permeability and the fuel combustion, their influence on the sinter yield and quality, their potential for energy saving and emission reduction was studied. The results show that the improvement of the bed permeability and of the fuel combustibility respectively and simultaneously, leads to an improvement of the sintering technical indices, to energy saving and emission reduction in the condition of super deep bed. At 1000 mm bed depth, and taking the appropriate countermeasure, it is possible to decrease the solid fuel consumption and the emission of CO2, SO2, NOx by 10.08%, 11.20%, 22.62% and 25.86% respectively; and at 700 mm bed depth, it is possible to reduce the solid fuel consumption and the emission of CO2, SO2, NOx by 20.71%, 22.01%, 58.86% and 13.13% respectively. This research provides the theoretical and technical basis for the new technology of sintering with super deep bed, achieving energy saving and reduction of emission.

Nowadays, finding ceramic materials with good physical-chemistry characteristics to make ceramic cups is no longer a big difficulty. However, the stability of the construction, the anti-penetration ability and the adaptability of the working profile of the hat face of the ceramic cup are of critical importance to prolong the campaign life of the ceramic cup itself and thus the BF hearth. In a lot of cases, the so-called “ceramic cup” is formed just by one, two or more rings of the standard-shaped ceramic bricks which are installed closely against the carbon hot face. In these linings, there are many penetrating linear joints from the hot face to the cold face through the ceramic lining. Both the overall stability of the construction and the anti-penetration ability of the lining are very poor. Therefore, the goal of installing a ceramic cup, to protect the carbon lining from the erosion of hot metal, would be difficult to achieve and the lifetime of the ceramic cup would not be long no matter what excellent materials were being used. However, an “Integrated Ceramic Cup” structure for the BF hearth is composed of special-shaped ceramic blocks which are all interlocked with each other. In such a construction, there is no linear breakthrough joint from the hot face to the cold face of the ceramic lining. A ceramic lining with this structure can effectively avoid hot metal and gases penetrating into and then through the joints of the ceramic lining to attack the carbon lining behind. As a result, the campaign life of the BF hearth, and also the campaign life of the blast furnace, would be prolonged. Nowadays the “Integrated Ceramic Cup” structure has been used in many modern blast furnaces and its significant performance has been proved.

The feasibility of increasing proportion of lump ores in blast furnace was investigated. The lab results showed that self-softening and melting properties of the lump ores were dramatically improved by interaction between sinters and lump ores found in the experiments. Furthermore, the collocation pattern of lump ores and ratio between lump ores was optimized according to interaction. When the proportion of lump ores was up to 23% or 27% at the excellent collocation pattern and appropriate ratio, the burdens still conformed to the requirements of ironmaking.