1、 毕业设计（论文） 外文翻译外文翻译 学生姓名 班 级 学院名称 机电工程学院 专业名称 机械设计制造及其自动化 指导教师 201 年 5 月 日 IMPACT OF ROCK HARDNESS ON FRAGMENTATION BY HYDRAULIC HAMMER AND CRUSHING IN JAW CRUSHER Abstract The physical and mechanical characteristics of intact rocks depend on the way of their formation, sustained deformations and the
2、 process of wearing a specific rock has been exposed to. These characteristics have a rather high influence on the technological process of extraction and dressing of mineral raw materials. However, the mechanical characteristics of rocks due to use of explosives for their extraction in the open pit
3、 have a more significant impact. The rock blocks extracted by blasting which are larger than the opening of the primary crusher are usually fragmented by hydraulic hammer. The paper presents the results of the testing of impact of rock hardness on fragmentation of rocks by means of hydraulic hammer
4、and during crushing in jaw crusher. The testing was carried out on the rock samples from five quarries. According to the obtained results the hardness has a considerably larger impact on the fragmentation energy by hydraulic hammer than on the crushing energy in jaw crusher. Introduction The product
5、ion of building crushed stone represents a considerable part of the production of mineral raw materials in the Republic of Croatia. Building crushed stone was until 2004 extracted on 250 exploitation fields according to the records of the Ministry of Economy, Labour and Entrepreneurship .Principally
6、,it is extracted from rock massif by blasting. The blasted rock mass is transported to separation where the stone is usually beneficiated by the crushing and sieving processes. The blasted rock mass contains oversized rock blocks, which are actually stone pieces larger than the opening of the primary crusher and which should have been fragmented before rushing. Oversized blocks are today almost always fragmented by hydraulic hammers.They have been frequently applied due to their numero
