Raw Materials

Thursday, October 4, 2018

《原来如此》 20180325 解析钢化玻璃 | CCTV科教

Thursday, March 15, 2018

Friday, March 31, 2017

Country Size Comparison (All 195 Flag Map Ranking)

Tuesday, May 17, 2016

https://zh.wikipedia.org/wiki/%E9%92%A8

https://en.wikipedia.org/wiki/Tungsten

tungsten is found naturally on Earth almost exclusively in chemical compounds.

Polycrystalline tungsten is an intrinsically brittle^[6]^[7] and hard material, making it difficult to work. However, pure single-crystalline tungsten is more ductile, and can be cut with a hard-steel hacksaw.^[8]

Tungsten's many alloys have numerous applications, including incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in TIG welding, superalloys, and radiation shielding. Tungsten's hardness and high density give it military applications in penetrating projectiles.

Because it retains its strength at high temperatures and has a high melting point, elemental tungsten is used in many high-temperature applications,^[62] such as light bulb, cathode-ray tube, and vacuum tube filaments, heating elements, and rocket engine nozzles.^[8] Its high melting point also makes tungsten suitable for aerospace and high-temperature uses such as electrical, heating, and welding applications, notably in the gas tungsten arc welding process (also called tungsten inert gas (TIG) welding).

黑钨矿、白钨矿、钨铁矿等矿物含钨。

重要的钨矿位于玻利维亚、美国加利福尼亚州和科羅拉多州、中国、葡萄牙、俄罗斯以及韩国。

中国出产全世界钨的75%。

通过使用碳还原钨的氧化物获得纯的金属。

全世界钨的贮藏总量估计为700万吨，其中约30%是黑钨矿，70%是白钨矿。但是目前大多数这些矿藏无法经济性地开采。按照目前的消耗量这些矿藏只够使用约140年。

另一个获得钨的方法是回收。回收的钨比钨矿含量高，事实上非常有利润。

纯钨是钢灰色至锡白色的坚硬金属。

在所有金属中钨的熔点最高(3415℃)蒸汽压最低。钨的防腐性能非常好，

大多数无机酸对其的侵蚀都很小。

在空气裡它的表面會形成一层保护性氧化物，但是在高温下会完全氧化。

在钢裡加入少量钨可以大為增高钢的硬度。

Friday, September 13, 2013

Natural Rubber

Rank	Area	Production (Int $1000)	Flag	Production (MT)	Flag
1	Thailand	3830585	*	3348897
2	Indonesia	3532620	*	3088400
3	Malaysia	1140029	*	996673	Im
4	India	1019550	*	891344	Im
5	Viet Nam	903212	*	789635
6	China, mainland	858850	*	750852
6	China	858850	*	750852
8	Côte d'Ivoire	273052	*	238717
9	Brazil	188158	*	164498
10	Sri Lanka	180952	*	158198
11	Myanmar	171148	*	149627
12	Nigeria	164140	*	143500	F
13	Philippines	160708	*	140500	*
14	Guatemala	118312	*	103435	Im
15	Liberia	72061	*	63000	F
16	Cameroon	63482	*	55500	F
17	Cambodia	49723	*	43471	Im
18	Mexico	43743	*	38243
19	Ghana	23088	*	20185
20	Ecuador	22493	*	19665	Im

http://faostat.fao.org/site/339/default.aspx

Wheat

Rank	Area	Production (Int $1000)	Flag	Production (MT)	Flag
1	China	13682901	*	117410300
2	China, mainland	13682855	*	117410000
3	India	12933827	*	86874000
4	United States of America	7709854	*	54413310
5	Russian Federation	5512901	*	56239990
6	France	4969905	*	38021000
7	Australia	3832378	*	27410076
8	Pakistan	3679654	*	25213800
9	Canada	3344883	*	25261400
10	Turkey	3145901	*	21800000
11	Kazakhstan	2750455	*	22732000
12	Ukraine	2282095	*	22323600
13	Argentina	2143267	*	14093728
14	Germany	2041946	*	22800000
15	Iran (Islamic Republic of)	1645981	*	13500000	*
16	United Kingdom	1319688	*	15257000
17	Egypt	1029603	*	8407126
18	Romania	937118	*	7131590
19	Morocco	876261	*	6017821
20	Poland	804877	*	9339200