Chapter 89 The Moon of Yesteryear
Spring days are naturally overcast, the clouds thin and deep.
Xie Ning looked at the darkening sky. A loud bugle call sounded, followed by rustling sounds. The outside suddenly became noisy. In mid-January, the Eastern Expeditionary Force assembled on the banks of the Yellow River to prepare for crossing. Now it was almost March, and they had probably already crossed the river.
She did not accompany the army, but instead stayed at the General Armory, leading a group of people to repair weapons. She would repair weapons in the morning and teach at the Red Army University in the afternoon, teaching knowledge about firearms and minerals.
Today happened to be the day when the people selected and dispatched by the organization gathered, so Xie Ning began to talk about "ore" this afternoon.
There were only twenty-six people attending the class, and the classroom was very simple, with only a broken blackboard. The school didn't provide much paper and pens, so everyone cherished them. In front of a few old desks and chairs sat officers sitting upright.
The reason for selecting officers instead of ordinary soldiers was that there were too few literate people. Even among officers, few were literate. Several years ago, the Red Army began to establish schools to train military and political cadres. Those who could enter Xie Ning's classroom were carefully selected.
Xie Ning didn't waste any words. After asking about the basic level of the students, he had a good understanding of the situation and then distributed the handwritten handouts.
She added, "You can take these handouts with you, but please keep them safe. There aren't many copies, and we need to leave some for those who come to study later." Her hands were numb from writing so much.
"My surname is Xie, and my given name is Changning. You can call me Teacher Xie." Xie Ning wrote his name on the blackboard.
Her current position is the director of the Ordnance Institute and concurrently the head of the Technical Department of the Red Army University. Her status is that of a technical expert. She receives two living allowances totaling ten yuan per month, which is quite high. Moreover, food, accommodation, and medical care are provided here, and she even has special meals. For the time being, she has no need to spend money.
The military allowance is tentatively set at three levels: one yuan per month for general personnel, two yuan per month for regimental-level officers, three yuan per month for officers above the regimental level, and the highest allowance of three yuan for engineering technicians.
"Hello, Teacher Xie!" The sudden, unified shout startled Xie Ning, almost breaking the chalk. She was heartbroken; chalk was so precious here.
"Okay, let's begin the lesson now."
First, let's talk about the types, requirements, and identification methods of ores. When smelting iron, the first thing we encounter is ore, and the most commonly used ores are iron ore and manganese ore.
To put it simply, ore is a rock made of metallic compounds and some non-metallic compounds bonded together. What we need to do is extract the metallic compounds inside... I have summarized the following common types of ore. One is black and shiny 'magnetite', which has an iron content of more than 60%. It looks like pig iron and can attract iron filings. If you scratch it on the bottom of a white bowl, it will leave a black line. This ore is very hard and cannot be cut with a knife.
Hematite has a hardness similar to magnetite, and its iron content is over 50%. However, it is not magnetic under normal circumstances, and only becomes slightly magnetic when heated.
It has two colors, and each color has a different shape. For example, the blackish-gray has an irregular shape, but it shines like pig iron. The brownish-red hematite is composed of very small, soybean-sized particles, which are very neat... Then there's hydrohematite... siderite...
"Teacher Xie." A colleague raised his hand straight, and Xie Ning gestured for him to stand up and speak.
"As you said, is it true that the lower the iron content of iron ore, the softer it is?"
Xie Ning took a sip of water and nodded slightly. "You could say that. Hematite contains about 40% iron and is relatively soft, so you can scratch it with a knife. Siderite contains about 30% iron and is also relatively soft, so you can scratch it with your fingernail."
For ores, the higher the iron content, the better. Iron ore usually has an iron content of around 20-70%. A content greater than 50% is considered rich ore, while a content lower than 50% is considered poor ore.
The ore must also contain few harmful impurities, otherwise it will affect the quality of the pig iron. If there are too many impurities, they should be treated before smelting, which I will discuss later. Now, let's continue with the last three requirements: 'ease of reduction', 'alkalinity content', and 'physical properties'.
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