Gravity Separators
Introduction
Gravity separation process is the earliest method that applied in mineral processing. According to the density difference among mines and the difference of gravity, fluid power and mechanical force in moving medium, mines realizes mineral grains separation through density difference, gravity separation method still occupies an important position in the contemporary mineral processing.
Applied ore：
Gravity separation process is widely applied in gold ore, tungsten ore, tin ore, manganese ore, mercury ore, titanium ore, lead ore, tantalum-niobium ores, galena, barite, fluorite ore, pyrite, limonite, hematite, antimony, chromium ore and ferrous metal.
Customer site 1-- Sudan 500t/d Gold Project
- Ore property :
- The plant was located in erosion hills, and paragenetic mineral of gold placer are mainly magnetite, ilmenite, followed by limonite and rutile.
- Project problem :
- Gold placer existed in native gold, the particle sizes was coarse from 0.1~1.0 mm, those that were less than 0.074 mm has little gold, and no colloidal clay, and it was washing gold placer. But the water shortage was the big challenge for this project.
- Our solutions :
- Yantai Group decided to adopted two-stage jig, shaking table concentration process, which directly produced gross gold and heavy concentrate. Combined with the project of water shortage and terrain topography, Yantai Group adopted mechanical mining and mechanical delivery, focused on building machine-processed plant, and gravity separation process has simple equipment and relatively perfect process, which not only saved cost, but also improved recovery rate of gold placer.
- Process indicator :
- Gold placer grade :0.811g/m3; Gross gold grade :85%; Recovery rate of gross gold 93.38%
Customer site 2-- Fujian 2000 t/d Wolframite Project
- Ore property :
- The tungsten ore was feldspar-quartz vein type deposit. The main metallic minerals were wolframite, followed by scheelite, The metallic minerals accounted for 3-5% of total amount of ore.
- Project problem :
- Wolframite was associated with quartz from 10~15mm to 0.01 mm; Scheelite was associated with pyrrhotite and other sulfide minerals, the particle size was about 0.2 ~ 0.01 mm. The raw ore contained 4% silt content and 6-7% water content.
- Our solutions :
- After the mineral processing experiments, Yantai Group decided to adopt three stage jig, four stage shaking table, mud and sand separation based on ore properties. Coarse, medium grain jig tailings were sent to rod mill, and the ground was returned to double vibrating screen, which formed a closed cycle. The shaking table is used in twice separation, coarse grain was returned to the closed cycle, the fine grain was returned the original work. Slime individual treatment, including coarse level table recovery, fine to original process. The pulp need to be handled separately, and shaking table recycling was adopted in the coarse grain, centrifugal separator recycling was adopted in the fine grain, ultimately the whole process obtained jigging rough concentrate, shaking table rough concentrate and fine mud rough concentrate.
- Process indicator :
- Concentrate grade :66.11%; Tailings grade :0.038%; Recovery rate :83.67%
Customer site 3-- Guangxi 1000t/d Tin Ore Project
- Ore property :
- The ore is cassiterite polymetallic sulfide ore. The main metals were tin ore, pyrite, and marmatite.
- Project problem :
- The metal minerals disseminated unevenly, most of them were immersed in vein or surrounding rock, and the aggregate grain is coarser. The tin ore was distribution as stripped, and alternated with various sulphides, especially associated with pyrite, and embedded with gangue.
- Our solutions :
- Yantai Group decided to adopted heavy medium primary, gravity separation-flotation- gravity separation combined process .Based on the fine grain of tin ore pulp and slow fall velocity, Yantai Group adopted centrifugal concentrator for roughing and discarded a large number of tailings. In addition, Yantai Group used 6s shaking table to process centrifugal concentrator coarse ore and spiral chute tailings, which simplified the production process, prevented the vicious cycle of middling, and maximized tin ore recovery. Compared with single tin concentrate separation process, gravity separation process increased 5~10% recovery rate, and the recovery rate of primary ore was improved by 1.5~2.0%.
- Process indicator :
- Ore grade : 0.68%; Concentrate grade :69.62%; Recovery rate :85.25%
