Taoist Alchemy is a spiritual practice that focuses on inner transformation and the pursuit of immortality. It is based on the belief that through specific techniques and practices, one can cultivate and refine their inner energy, or qi, to achieve physical, mental, and spiritual balance and harmony. The key teachings of Taoist Alchemy can be summarized as follows:

1. The Three Treasures: In Taoist Alchemy, there are three main aspects of one's being that are considered to be the foundation for inner transformation and immortality. These are known as the Three Treasures - Jing (essence), Qi (energy), and Shen (spirit). It is believed that by cultivating and balancing these three treasures, one can achieve health, longevity, and spiritual enlightenment.

2. The Microcosmic Orbit: The Microcosmic Orbit is a key practice in Taoist Alchemy. It involves circulating and refining the qi throughout the body, following a specific pathway known as the "small heavenly cycle." This practice is believed to help purify and strengthen the Three Treasures, leading to improved physical and mental well-being.

3. Inner Alchemy: Inner Alchemy is the process of transforming and refining one's inner energy, or qi, to achieve immortality. It involves various practices such as meditation, breathing techniques, and visualization, all aimed at cultivating and directing the qi towards spiritual growth and enlightenment.

4. Balance and Harmony: Taoist Alchemy emphasizes the importance of balance and harmony in all aspects of life. This includes balancing the yin and yang energies, as well as finding harmony between the physical, mental, and spiritual aspects of one's being. It is believed that by achieving balance and harmony, one can achieve inner peace and longevity.

5. Nature and the Five Elements: Taoist Alchemy draws heavily from the principles of nature and the Five Elements (wood, fire, earth, metal, and water). These elements are seen as the building blocks of the universe and are believed to have a profound influence on our physical, mental, and spiritual well-being. By understanding and aligning with the cycles and energies of nature, one can achieve greater harmony and balance within themselves.

In conclusion, the key teachings of Taoist Alchemy revolve around the cultivation and refinement of one's inner energy, balance and harmony, and the pursuit of immortality through spiritual growth and enlightenment. Through dedicated practice and cultivation of the Three Treasures, one can achieve physical, mental, and spiritual well-being and ultimately, transcendence to a state of immortality.