Can the experimental multi zone rotary furnace be ventilated with gas?

The experimental multi temperature zone rotary furnace can pass gas, and the gas inlet function is one of its core designs, which can meet complex experimental requirements. The following is an explanation from four aspects: gas types, functional roles, application scenarios, and operating points:

1. Types of gases that can be introduced
Experimental multi zone rotary furnaces typically support the introduction of multiple gases, including but not limited to:
Inert gases, such as nitrogen (N ₂) and argon (Ar), are used to isolate air and prevent material oxidation at high temperatures (such as sintering of lithium battery cathode materials and metal powder metallurgy).
Reducing gases: such as hydrogen (H ₂) and carbon monoxide (CO), used for reduction reactions (such as reduction of laterite nickel ore and treatment of vanadium titanium magnetite).
Activated gas: such as water vapor (H ₂ O), used for specific activation processes (such as activated carbon water vapor activation).
Mixed gas: Customize the ratio according to experimental requirements (such as a mixture of hydrogen and nitrogen).

2.The core function of gas inlet
Atmosphere protection
Isolate oxygen at high temperatures to prevent material oxidation or decomposition. For example, in the sintering of ternary materials for lithium batteries, an oxygen atmosphere can promote the ordered growth of layered structures and improve the initial charge discharge efficiency (≥ 92%).
In metal purification, inert gases can avoid the introduction of impurities and improve purity (such as solar grade silicon purity ≥ 99.9999%).
Participate in chemical reactions
Participate in the process as a reactant or catalyst. For example, in Fischer Tropsch synthesis (FTS), hydrogen and carbon monoxide are catalyzed to produce liquid fuel; In selective catalytic reduction (SCR) of NOx, ammonia (NH3) reacts with nitrogen oxides to produce nitrogen gas and water.
Humidity control
By introducing steam to regulate the humidity inside the furnace, it is suitable for evaporation or hydrolysis reactions in industries such as fertilizers and ceramics. For example, in the ceramic expansion process, precise control of sintering temperature (1150-1250 ℃) and water vapor partial pressure can achieve a shale expansion ratio of 3-5 times.

3. Typical application scenarios
Heat treatment of lithium battery materials
Sintering of positive electrode material: Under an oxygen atmosphere, multi temperature zone temperature control is used to achieve ordered growth of layered structure of ternary materials (NCM/NCA), improving cycling stability (capacity retention rate ≥ 85% after 1000 cycles).
Processing of silicon-based negative electrode materials: The rotary furnace alleviates the volume expansion of silicon particles (≤ 150%) through dynamic mixing, combined with carbon coating processes (such as CVD deposition), to improve the first efficiency (≥ 88%) and specific capacity (≥ 1500 mAh/g).
Metallurgical Industry
Reduction of laterite nickel ore: A reducing atmosphere with a CO concentration of 35% is used to achieve a nickel metal recovery rate of over 92% and a cobalt leaching rate of 85% at 800-1000 ℃.
Vanadium titanium magnetite treatment: Through selective reduction technology, 98% of the titanium component is converted and retained at 1300 ℃, providing high-quality raw materials for the subsequent production of chlorinated titanium dioxide.
environmental science
Recycling of waste lithium batteries: Multi temperature zone temperature control combined with reducing atmosphere (H ₂/CO) is used to achieve stepwise reduction of LiCoO ₂ positive electrode material (such as 600 ℃ Co∝ O ₄ → 800 ℃ CoO), improving metal recovery rate (Li ≥ 95%, Co ≥ 90%).
Hazardous waste treatment: In the dioxin decomposition rotary furnace, maintain a high temperature zone above 850 ℃ for more than 2 seconds, and cooperate with the rapid cooling tower to reduce the flue gas to 200 ℃ within 0.5 seconds, achieving a dioxin emission concentration of less than 0.1ng TEQ/m ³.

4. Operation points and safety regulations
Gas flow control
Accurately adjust the gas flow rate (such as hydrogen flow rate of 50-200 mL/min) through a mass flow meter to avoid flow fluctuations affecting reaction uniformity.
When introducing flammable gases (such as H ₂), hydrogen alarm devices and emergency shut-off valves should be equipped to ensure safety.
Vacuum and atmosphere switching
External vacuum pump can achieve high vacuum degree (≤ 10 Pa) inside the furnace, and then introduce the target gas to establish a protective atmosphere, avoiding residual air interference in the experiment.
When switching gases, it is necessary to first empty the existing gas in the furnace to prevent mixing and explosion (such as mixing H ₂ and O ₂).
Sealing inspection
Regularly inspect the sealing rings of the furnace door, air inlet, exhaust outlet and other parts to ensure no leakage and maintain a stable atmosphere inside the furnace.
At high temperatures, the sealing material needs to be corrosion-resistant (such as fluororubber or perfluoroether rubber).