Gold wire Hill mine located in North Carolina, is the world's largest spodumene origin. The typical composition of the pegmatite deposit in the mine is: %:
Spodumene | Feldspar | quartz | White mica Amphibole | Other minerals |
19~22 | 28～33 | 25~35 | 5~15 | Small amount |
Among them, Li 2 O is about 1.5%, and BeO is 0.04% or more. The district had beneficiation plant using different processes, 50s using heavy media beneficiation and reverse flotation, subsequently to change, since the 1970s, the gradual introduction of the mine concentrator flotation process.
1. Jinsishan reverse flotation process
The reverse flotation process of the Jinsishan Concentrator is to add dextrin or starch to the spodumene in the alkaline medium caused by lime, and use the cationic collector to float the silicate-like gangue mineral. The product in the tank is lithium. Pyroxene concentrate can be sold as a chemical grade product. In order to reduce the iron content in the lithium concentrate, the above concentrate needs to be further selected. For this purpose, hydrofluoric acid, resinate and foaming agent flotation iron mineral are added, and the obtained lithium concentrate can be sold as a ceramic industrial raw material. . The foam concentrate obtained by flotation of gangue minerals can be further subjected to separation flotation to obtain mica concentrate, feldspar concentrate and quartz concentrate. The reverse flotation process used by the Jinsishan Concentrator in the 1950s is shown in Figure 1. At that time, the ore grade was about 1.5% Li 2 O, the lithium concentrate contained Li 2 O higher than 6%, the recovery rate was 70% to 75%, the total drug consumption was 2.5 to 3 kg/ton, and the plant selection scale was 360 tons/day.
Fig.1 The reverse flotation process of spodumene in Jinsishan Plant
Second, Jinsishan positive flotation process
In 1976, North Carolina State University conducted a research on the positive flotation process of the Jinsishan spodumene ore. Through the semi-industrial test, the satisfactory index was obtained: the spodumene concentrate grade was 6.3% Li 2 O, and the operation was recovered. The rate (excluding slime) was 94.5%, and the recovery rate of raw ore was 88.4%. Since then, the process has been adopted by the US Lithium Company of the Jinsishan Mining Area and the concentrator of the Ford Mineral Company. The processing capacity of the two plants is 2,400 tons / day and 2,600 tons / day, respectively, 480 tons and 530 tons of daily production of spodumene concentrate, 1300 tons / day of feldspar, 750 tons / day of quartz and 100 tons / day of mica . The lithium concentrate grade of the plant is 6.3% Li 2 O, the recovery rate is 75% to 78%, and the drug consumption is slightly more than 1 kg/ton. The production process is shown in Figure 2.
Figure 2 Jinsishan spodumene flotation process
Welding elbow is shrimp "turn", it can be in the pipe or plate cutting after welding and become, and its specifications can be large. The number of nodes and the bending radius are determined by the producer. Welding bending is not very smooth, both of the bending radius is not large, generally about 1 times the diameter of the pipe.
Photo of Welded Bend:
Classification of welding elbow, according to its radius of curvature,
45 degree elbow
Can be divided into long radius elbow and short radius elbow. Long radius elbow refers to its radius of curvature is equal to 1.5 times the diameter of the tube, that is, R=1.5D. short radius elbow refers to its radius of curvature is equal to the outer diameter of the pipe, that is, R=D. D in the formula is the elbow diameter, and R is the radius of curvature. The most commonly used for 1.5D elbow, if not specified in the contract is 1D or 1.5D, then it is to optimize the use of 1.5D. GB/T12459-2005, GB/13401-2005, GB/T10752-1995., is the most commonly used executive standard in China.
Pressure grade classification
If according to the pressure level, there are about seventeen, and the United States pipe standards are the same, there are: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS,; Sch
180 degree welding elbow
80, Sch100, Sch120, Sch140, Sch160, XXS, which is the most commonly used STD and XS two. According to the angle of the elbow, 45 degree elbow, 90 degree elbow and 180. Species as a result of the elbow is a lot, when ordering, order is often taken as described in the following methods: such as "LR STD 90 8", said long radius, pressure rating for STD, 90o 8 "elbow; and as," 45 DEG SR XS 4 "said short radius, pressure rating for the XS and 45 degrees of 4" elbow. The above is about the classification of the elbow. Three links, there are two kinds of general. The diameter of the three equal diameter is equal to the diameter of three links, and both ends are the same diameter, but the diameter of the junction is different from that of the other two diameters. The method is as follows: for the equal diameter three links, such as the "T3" three general, the outer diameter is 3 inches and three inch diameter. For different diameter three links, such as the "T4 x 3.5 x three" means that the same diameter of four inch diameter of 3.5 inches of 4 inch diameter. The pressure level is the same as that of the elbow, and the range is the same.
This is the big head, method. Head size of said method is big diameter multiplied by the head diameter, for example "8 x 6" said big head with a diameter of 8 inches and head diameter is 6 inch head size.
Material division of welding elbow
Carbon steel: A234 WPB ASTM/ASME, WPC
Alloy: A234 WP 1-WP 12-WP ASTM/ASME 11-WP 22-WP 5-WP 91-WP911 15Mo3, 15CrMoV, 35CrMoV
Stainless steel: A403 WP 304-304L-304H-304LN-304N ASTM/ASME
A403 WP 316-316L-316H-316LN-316N-316Ti ASTM/ASME
A403 WP 321-321H ASTM/ASME A403 WP 347-347H ASTM/ASME
Low temperature steel: A402 WPL3-WPL ASTM/ASME 6
High performance steel: A860 WPHY 42-46-52-60-65-70 ASTM/ASME
structure
Welding elbow appearance
As the appearance of the welding elbow, then we say that the appearance of the welding elbow bar. Welding elbow appearance are fixed, of course, the general welding elbow appearance is according to different steel tube and to choose the different knowledge of welding elbow, so, in order to ensure the welding elbow appearance, usually Steel Pipe in the future, if not been yard rain washing off, then welding elbow after high temperature push general weld appearance of the elbow is appear out of the blue, of course, if the rain washed, we in high temperature after heating, heating welding elbow surface color are red. But overall, we guarantee tube is washed by the rain is very difficult, because is yard in summer is rain fog water washed, then push the system out of the welded elbow surface is red, too.
Technical requirement
Geometric dimensions include outside diameter, inside diameter and wall thickness. Also requires control
Radius of curvature. For example, the radius length is 1.5D, and the radius of curvature must be within the range of tolerances required. Due to these fittings, most used for welding, in order to improve the welding quality, end vehicles into the groove, leave a certain angle, side band, this requirement is quite strict, edge thick, at an angle of number and range of deviation provisions, geometric size than pipe much many. The surface quality and mechanical properties are basically the same as that of the tube. In order to facilitate welding steel, and the connecting pipe are the same. Fourth, is all the pipe fittings should be through the surface treatment, the inner and outer surface of the oxide scale through shot blasting, and then coated with anticorrosive paint. This is not only for export needs, in addition, in the country is to facilitate the transport to prevent rust oxidation, to do this work. Fifth is the packaging requirements, for small pipes, such as export, you need to do wooden, about 1 cubic meter, this provision in the case the number of elbows about not more than a ton, the standard allows the suit, large sets of small, but the total weight usually do not more than 1 ton. For large to a single package, like 24 "must be a single package. The other is labeled packaging, labeling is to indicate size, number, batch number, manufacturer trademark. In the pipe to be stamped on stamp, and attached to the packing list and the quality book file.
Welded Bend
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