| In recent years,with the growing aggravation of the degree of low-grade, fine-grained and complicated mineral resources, coupled with the structural contradictions of energy and mines in our country, how to further improve the utilization level of the ultra-lean ore and how to extend of the service length and the capacity of old mines and develop the sustainable abilities of resource-cities are important problems which should be solved. It is imminent to establish efficient and reasonable technologies and processes for the ultra-lean ore discarded by previous mining process. In this article the X-ray radation pre-sorting technology is a method that uses the intensity of the characteristic X-ray of the ores surface after excitated by the primary X-ray. It is a new, efficient, environmental protection separation process for low-grade mineral resources. The technology is the new combination product of atomic physics and automated sorting so that there is no successful application experience in the domestic. The working principles and process parameters of the X-ray pre-sorting machine were studied when copper and molybdenum mine ultra-lean ores were as test ore samples in this subject. This paper establishes a beneficiability evaluation system of ultra-lean ore and analyzes the sources of errors in pre-sorting process as well as researches flotation separation behavior of the ore after preconcentration. The success of the joint process research is a major technological innovation and breakthrough for mine waste rock resource utilization.Based on Moseley’s Law, this paper established the principles and steps of judging unknown elements in the ores and use "characterisitic-disspersive ratio" method to reflect the grade level. This study laid a theoretical foundation to utilize ultra-lean ore by X-ray radation pre-sorting technology.This paper systematically investigated the influences of excitation voltage, the number of filter, detection distance, feed moisture, slime contention, feed frequency, excitation surface, eparation threshold on the precontention indexes of the 1 ultra-lean copper ore of Fushun Liaoning province. The results showed that feed moisture had a little influence on the final indexes, while the slime contention of the sample surface deteriorated the selection performance on various grade ores seriously. Feed frequency had different influence on different size class feeding. Although excessive frequency can improve the handling capacity, it can worsen indicators of the fine size-class feeding. However, it did not affect the coarse fraction. The analysis of characterisitic-disspersive ratio, XRD, counting statistical error and photon counting uncertainty error showed that the optimum working conditions of the preconcentration machine could be achieved under the condition of excitaion voltage of 36kV, primary filter number of 6, detection distance of 4cm. On this basis, this test achieved the best separation indexes that the final copper concentrate grade was 1.15% with a recovery of 70.8% when the separation threshold of 0.11.On the basis of process mineralogy study of copper ore after preconcentration, this paper studied the flotation separation behaviors of chalcopyrite, sphalerite, pyrite in the ore under the optium kind and dosage of collector, regulator and frother. Under the premise of preferential flotation of chalcopyrite, sphalerite and pyrite, the "stepwise-allometric"process was put forward in order to recovery copper according to the liberation nature of chalcopyrite. The closed-flow test result showed that it can achieve a Cu concentrate in the first-step rougher with the Cu grade of 20.9% and a recovery of 40.78%, the mixed concentrate of the second and third step rough can achieve a final concentrate with the Cu grade of 23.4% and a recovery of 49.8% after four stage cleaners. So the grade and recovery of mixed copper copper concentrate is 22.25% and 90.58% respectively. The copper tailing can get a Zn concentrate with grade of 48.40% and a recovery of 70.99% through one stage roughing, one stage scavenging and four stage cleanings. The Zn tailing can get a S concentrate with grade of 43.50% and a recovery of 67.22% through one stage roughing, one stage cleaning and one stage scavenging.This paper also carried out preconcentration tests on ultra-lean Mo ore of Chaoyang Liaoning province in order to inspect the adaptability of preconcentration machine on elements with different atomic number. The study method was like with the copper ore. The results showed that the optimum of process parameters of ultra-lean Mo and Cu ore were not the same. Each unit of the preconcentration machine was at its best with excitation voltage of 45kV, the primary filter number of 6 pieces.Process Mineralogy of Mo ore was studied by means of SEM、EDS、MLA.On this basis,this article studied the flotation behavior of MoS2 under the condition of the different kind and dosage of collector, regulator, frother. The open-circled flowsheet result showed that the flotation process can achieve a product with the Mo grade and recovery was 45.7% and 47.9% respectively.Studies on the sources of preconcentration error indicated that the enhancement effect, structureand surface effects of different elements in the ultra-lean ore can cause characteristic-dispersive ratio and the element content of the ore block appear inconsistent. This study formulated evaluation index of preconcentration according to the ultra-lean copper sulfide and molybdenum sulfide ore. Whether some ore need be processed by preconcentration was judged from the following aspects, that is the feeding size, grade distinction and the related degree of the really ore grade and characteristic-dispersive r atio. The research showed that size of the ultra-lean Cu ore and Mo ore studied in th is article was coarse and it was suitable for handling by preconcentration process. The coefficient of variation of grade and the value of Mo’law all indicated that that ultra-lean ore was strong washability. The study of the related degree of the really ore gra de and characteristic-dispersive ratio showed that it was reasonable to adopt characteris tic-dispersive ratio as scattering line background internal standard method of theoretical basis to representing the grade of ore.The combined process established in this article called X-ray preconcentration-flotation is a major technological innovation and breakthrough for resource utilization of ultra-lean ore and mine mullock. This joint process has incomparable superiority of other technologies. The research in this article has important theoretical value and guiding significance to localization research and upgrading every parameter of this pre-sorting machine. |
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