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The man alchemy with fire, gold flows with fire, and stone burns with fire and coke, and the physical properties are different. In today's words, mercury and alum, the two also have special physical properties.
Mercury, at room temperature, is only a liquid metal. Silver shines, and the texture is agile. It resembles a living thing. When touched, it rolls and disperses, making it difficult to hold. Its density is quite large, heavier than ordinary things. Although it is a liquid, it has a heavy feeling. And mercury is volatile, gradually dissipating and invisible in the air, and its vapor is toxic and should not be careless.
As for alum, there are many kinds, common ones are alum, green alum and the like. Alum is mostly crystalline solid, regular in shape, or lumpy, or granular. Its color varies, alum is as white as snow, and green alum is as green as blue. Alum is soluble in water, and when dissolved, it either clarifies the water, such as alum purifies water, or changes the color of the water, such as green alum dissolves water.
The liquid fluidity of mercury is significantly different from the solid stability of alum. The volatile nature of mercury and the relative stability and non-volatilization of alum are also the major differences between the physical properties of the two. And mercury has the luster and density of metals, while alum does not have this typical metallic property, and is a salt. There are also many differences in chemical properties between the two, but in terms of physical properties alone, the unique liquid, volatile, high density of mercury and the solid crystallization and solubility of alum in water constitute distinct physical property differences.

Mercury has different properties. It is a liquid metal that flows at room temperature and has many unique chemical properties.
The chemical activity of mercury is lower than that of some metals. However, under certain conditions, it can also react with other substances. For example, mercury can combine with sulfur, and when the two meet, they react quickly to form mercury sulfide. This reaction is quite wonderful. Sulfur can firmly bind mercury so that it no longer flows freely. This is a common method for dealing with mercury leakage.
Mercury can also interact with oxygen. When heated, mercury reacts with oxygen to form mercury oxide. This reaction can be seen in the experiment. The surface of the heated mercury gradually changes, and the color and texture are different from before.
Furthermore, mercury ranks among the metals in the order of activity. Although it is difficult to replace the hydrogen in the acid, it can react with some metal salt solutions. If mercury is placed in a silver nitrate solution, mercury can replace silver from the silver nitrate solution. On the surface of mercury, silver can be seen precipitating, which highlights the characteristics of mercury in chemical reactions.
Mercury compounds also have different chemical properties. Such as mercury chloride, which has certain oxidizing properties. Mercury sulfide, on the other hand, has relatively stable chemical properties and bright color, and is often used in pigments.
Mercury has unique chemical properties. It is involved in chemical reactions, or combines with other substances, or participates in displacement reactions. Its complex and changeable properties make it increasingly curious to explore its chemical wonders.

In the field covered by "Tiangong Kaiwu", the main uses of mercury (mercury) are quite extensive.
First, in the field of metallurgy, mercury is often used to extract metals. For example, in the process of mercury smelting in cinnabar (mercury sulfide), the volatile characteristics of mercury are used to separate mercury from the ore by heating cinnabar. At the same time, the amalgam method plays an important role in the extraction of precious metals such as gold and silver. Mixing gold and silver-containing ores with mercury can form amalgam with gold and silver, and then evaporate the mercury by heating and other means to obtain high-purity gold and silver. This method is of great significance in the development of ancient mining, which greatly improves the efficiency and purity of metal extraction.
Second, in alchemy, mercury is an extremely critical raw material. Ancient alchemists believed that through specific formulations and refining methods, mercury could refine medicinal pills with miraculous effects, or make people immortal or cure intractable diseases. Although this concept seems to lack scientific basis today, in the cultural and cognitive background of the time, alchemy promoted the development of mercury-related knowledge and technology, prompting people to continue to explore the properties and reactions of mercury.
Third, in the field of medicine, mercury also has applications. The ancients discovered that certain compounds of mercury have certain medicinal value, such as light powders (mercurous chloride), which are used in some external formulas to treat skin diseases. However, due to the toxicity of mercury and its compounds, it needs to be used with extreme caution, and improper dosage control can lead to serious consequences.
Fourth, mercury also has traces in daily life and the production of handicrafts. For example, in ancient mirror making, some processes used amalgam to evenly apply metal to the surface of glass or other substrates to form a reflective layer, thereby creating mirrors.

To make dicyanohexamine, there are three methods.
One is the thermal polymerization of urea. Take an appropriate amount of urea and place it in a high temperature environment to decompose and polymerize it by heat. Urea loses ammonia first to form cyanic acid, and cyanic acid polymerizes with each other to form dicyanohexamine. This process requires precise temperature control. If the temperature is too low, the reaction will be slow, and if it is too high, the product will be easily decomposed. And it is necessary to pay attention to the reaction time, which is insufficient, and the polymerization is not complete; if the time is too long, or impurities are generated.
The second is the condensation method of dicyanoamide. Under specific conditions, dicyanoamide undergoes its own condensation reaction. When the temperature and pressure are suitable, and there is an appropriate catalyst involved, the dicyan The choice of catalyst is crucial, which can speed up the reaction rate and increase the yield. At the same time, the pH of the reaction system also needs to be strictly controlled, otherwise it will affect the purity and structure of the product.
The third is the method of cyanamide polymerization. Under the action of the initiator, the cyanamide monomer starts the polymerization process. The initiator needs to be used with precise dosage. If it is too small, it will be difficult to start the polymerization, and if it is too much, the reaction will be out of control. During the reaction process, it is necessary to always pay attention to the state of the system and adjust the conditions in a timely manner, so that the cyanamide molecules can gradually polymerize, and finally obtain dicyanohexamine.
The above methods have their own advantages and disadvantages. When actually preparing, it is necessary to comprehensively consider the cost of raw materials, equipment conditions

Mercury is a highly toxic substance, and many matters need to be paid special attention when storing and transporting it.
When storing mercury, choose the first heavy container. When using thick and well-sealed metal or glass containers, because mercury is highly corrosive, ordinary materials are prone to erosion and leakage. If mercury is stored in iron cans, mercury will come into contact or react with iron for a long time, damaging the tank wall. And the selected container must have a reliable sealing cover to prevent mercury from evaporating into the air, causing environmental pollution and human harm.
Furthermore, the storage environment is very critical. It should be placed in a cool, ventilated and temperature-stable place, away from direct sunlight and high temperature environments. Due to the increase in temperature, mercury evaporation accelerates. If placed in the hot sun or high temperature workshop, a large amount of mercury evaporates, and people are susceptible to mercury poisoning by inhalation.
When transporting mercury, the packaging must be firm. First seal the mercury in the inner packaging container, then wrap it with buffer material, and put a strong outer packaging box to prevent collision and vibration during transportation. And the transportation vehicle also needs to choose a special one, with good ventilation and anti-leakage facilities.
Transportation personnel also need to undergo professional training, familiar with mercury characteristics and emergency treatment methods. During transportation, regularly check whether the packaging is in good condition. If there is any leakage, deal with it according to the standard process quickly. Evacuate the crowd first, isolate the site, and then use special tools to collect mercury, cover the residual mercury with sulfur powder, and promote its reaction into difficult-to-volatilize mercury sulfide to reduce harm. Therefore, the mercury is safe during storage and transportation.