A half year later, the funds raised in the stock market had reduced the company's debt-capital ratio from 187 percent to 33 percent, and added as much as 24 billion yuan to Zhang's fortune, making her the wealthiest self-made woman in the world.

"My sister hates lazy people the most. She is always energetic and more diligent than any other person I know," says Zhang Yin's sister Zhang Xiubo. "We obey her unconditionally."

Five of Zhang's sisters and brothers as well as her husband help in the business, but Zhang denies kinship plays a key part in her management.

"Out of the whole family, only one brother has entered the company's management. I chose him for his ability," she said. "My husband used to be a doctor, but I discovered his talent and convinced him to do business. They have proved to do an excellent job."

A mother of two, she believes balancing career and family is the key to the success of a businesswoman.

Her achievements could encourage China's promotion of a resource-efficient society and a sustainable economy with 10 million tons of scrap paper yet to be recycled each year.

However, those who want to become next Zhang Yin are challenged by the country's lack of a professional paper recycling system, with most of it buried or burned without being sorted from other garbage.

Li Jianhua, a national legislator, proposed to the National People's Congress in March that China should make laws to improve its waste paper recycling system by establishing special recycling agencies and enacting unified standards for sorting waste paper.

"The recycling of paper is the way to solve the raw materials shortage that is the bottleneck of China's paper-making industry, and a requirement for building a resource-efficient society," said Li.

Until then, Zhang Yin is likely to retain her crown as the "queen of waste paper".