Study On The Prediction Of Rare Metal Deposits In Lanniba-heihaizi Mining Area In Western Sichuan By Geo-electrochemical Integrated Technology

Lithium,beryllium and other rare metals are key minerals that are in urgent need of shortage in China and play an extremely important role in the national aerospace,national defense and new energy fields.The Jiulong area in western Sichuan is located in the Yajiang residual basin on the southern margin of the Songpan-Ganzi orogenic belt.It is an important distribution area of pegmatite-type lithium-beryllium deposits in China.The geological survey of Lanniba-Heihaizi beryllium mining area is relatively weak and the research degree is low.In order to solve the problem of looking for beryllium and rare metal deposits in this mining area,the research on prospecting prediction of geoelectrochemical integrated technology is carried out in this area,The feasibility study of prospecting method is carried out on Line 4 above three beryllium ore bodies controlled by existing projects,and the prospecting prediction research is carried out mainly by crossing method.The following results are obtained:（1）The feasibility test of prospecting was carried out on Line 4 above No14,No18and No27 beryllium ore bodies.The analysis results show that the geoelectric extraction anomalies of Li,Be,Rb,As,Nb,Ta,Th,As and W and the soil thermal release mercury anomalies correspond well with the overlying three beryllium ore bodies,which can better indicate the occurrence location of beryllium and rare metal deposits,indicating that it is feasible to find beryllium and rare metal deposits in high-altitude landscape areas by geoelectrochemical technology.（2）Through the mathematical statistical analysis of Li,Be,Rb,As,Nb,Ta,W and Th in beryllium mining area,combined with the test and analysis of ore body samples in the study area,it is determined that the main ore-forming elements in the study area are Be,Li,Rb,Nb and Ta are associated ore-forming elements,and W,As and Th are indicative elements for finding rare metal deposits.（3）The single element is normalized processing,and the corresponding objective weight is calculated by principal component analysis and entropy method,The weight coefficient of each element was calculated by the difference coefficient method.Finally,the comprehensive objective weight of single element was calculated by linear weighting method,and three groups of factors F₁（Li-Be-Rb）,F₂（Nb-Ta-Th）and F₃（W-As）were obtained.The cumulative frequency method is used to delineate the abnormal inner zone of single element and element combination by 85%.The Surfer25is used to draw the plane anomaly map,and the correlation between the anomaly and the geological metallogenic conditions is described.（4）The linear weighting method is used to calculate the normalized comprehensive index.The normalized comprehensive index anomaly and the known ore body test are carried out on Line 4 above the known ore body,which shows that the normalized comprehensive index is highly feasible.The metallogenic potential of’medium,good and excellent’is evaluated for the measuring points in the inner zone of normalized comprehensive index anomaly.Based on the normalized comprehensive index of the measuring point as the base map,the abnormal inner zone of the single element and the combined element is nested,combined with the metallogenic geological conditions,the Li-Be-Rb and Nb-Ta target areas are divided,and the target areas of class I,class II and class III are delineated.The study shows that the class I target area can be used as the key research area for further prospecting.