Granite belongs to igneous rock, which is composed of quartz feldspar. Its hardness reaches about hs7-8, which is very close to diamond. Granite has higher hardness than marble, so it is difficult to process, but it is resistant to acid, weathering and corrosion. It is not easy to be weathered and metamorphosed, and its appearance color can be maintained for more than 100 years. Therefore, granite caves are used as protective shelters for important national nuclear military equipment in modern times to avoid being damaged in wartime.

花崗巖的特性，的耐磨損性，耐腐蝕，韌性好，抗風化，吸水性較好，十分適合做石磨，故花崗巖石磨為石磨鼻祖。色澤光度可保持千百年以上，的“埃及金字塔”“古希臘神廟”“北京人民英雄紀念碑”均很多使用花崗巖，保證千百年后留給后人無缺如初。

Granite features excellent wear resistance, corrosion resistance, good toughness, weathering resistance, good water absorption, it is very suitable for making stone mill, so granite stone mill is the ancestor of stone mill. The color and luminosity can be maintained for more than a thousand years. The famous "pyramid of Egypt", "ancient Greek temple" and "monument to the people's Heroes in Beijing" all use granite to ensure that there will be no shortage for future generations after thousands of years.

青石歸于碳酸巖硬度較低，硬度一般為2-2.6左右，青石材質較脆，耐磨性和抗風化性較差，色澤也只能到達50%左右，拋光后作用不理想，長處：自然界存量遍廣，全國本錢較低，對制作工人要求也不高，適合廠家量大出產。

Bluestone belongs to carbonatite, the hardness is generally about 2-2.6, bluestone material is brittle, the wear resistance and weathering resistance is poor, the color can only reach about 50%, the effect after polishing is not ideal, advantages: the natural stock is wide, the national capital is low, the requirements for the production workers are not high, suitable for large-scale production.

青石的比砂巖的好，由于青石的硬度比砂巖的高，砂巖吸水，不耐風化，容易碎，硬度低，研磨性差，僅僅容易挖掘和制造而言。

Bluestone is better than sandstone. Because bluestone has higher hardness than sandstone, sandstone absorbs water, is not resistant to weathering, is easy to break, has low hardness and poor abrasiveness, and is only easy to excavate and manufacture.

雜糧加工，這里講的是將小麥、玉米進行簡加工，通過面粉機或者玉米脫皮拋光機、制糝機加工成用于食品、飼料、化工等等各個領域的原料。小麥可以加工成精粉、特一粉、通粉等各個不同精細和要求等級的面粉，玉米經過加工可以成為大、中、小及粉狀的顆粒，這些加工后的產品都可以用于日常生活和化工科學領域等各個方面，可謂是市場非常的廣泛，需求量也是非常之大，人人離不開小麥，人人離不開玉米。所以說，選擇這一行，不會有錯的，有需求就會有市場。

Coarse cereals processing, here is about wheat, corn simple processing, through flour machine or corn peeling polishing machine, grits machine processing for food, feed, chemical and other fields of raw materials. Wheat can be processed into refined flour, special one flour, Tong flour and other different fine and required grades of flour, corn can be processed into large, medium, small and powdery particles, these processed products can be used in daily life and chemical science and other fields, it can be said that the market is very wide, the demand is also very large, everyone can't do without wheat, everyone can't do without wheat No corn. Therefore, there is no mistake in choosing this line. If there is demand, there will be a market.