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An abandoned phosphate mine in Central Florida's Bone Valley.

Nichols Phosphate Mine

Several buildings at the Nichols Phosphate Mine | Photo © 2018 Sugarbomb​

When one hears the term 'Bone Valley' it’s understandable that they would imagine something akin to the elephant graveyard from The Lion King. But rather than referring to any ominous happenings, the name actually refers to an ancient fossil bed located 20 to 40 feet below parts of Central Florida. This area known as Bone Valley includes portions of modern-day Hardee, Hillsborough, Manatee, and Polk counties.

Florida, specifically this Bone Valley region, contains the largest known deposits of phosphate in the United States. These phosphate deposits were formed over millions of years by the accumulation of organic matter on the ocean floor. Until recently (at least in terms of the Earth's history) the land that is now Florida was below a warm, shallow ocean. About 23 million years ago sea levels dropped low enough that portions of Florida became dry land and animals began to inhabit this area for the first time. However, this was long after the last dinosaurs had gone extinct, which explains why there are no dinosaur fossils found in Florida, even in the deep subsurface.

Nichols Phosphate Mine

Nichols Phosphate Mine | Photo © 2018 Sugarbomb​

Phosphate is the natural source of phosphorous, an essential ingredient in many products, especially fertilizers. Phosphate can also be turned into phosphoric acid, which is used in everything from food and cosmetics to animal feed and electronics.

In the early 20th century, Bone Valley attracted many commercial mining companies to the area. Early on, the mining process was slow. It would take miners years to mine only 15 acres working with only a pickaxe and wheelbarrow. By 1910, mechanized steam shovels greatly helped streamline the process. By the 1920s, Florida phosphate mines supplied approximately 75% of the phosphate used by farmers and gardeners in the United States, and many companies also sold and shipped phosphate overseas.

The town of Nichols, Florida was founded in 1905 by the Virginia-Carolina Chemical Company in order to house workers and their families. Approximately 34 miles east of Tampa, it was named after nearby Fort Nichols, a fort used by the United States in the Seminole Wars. The community consisted of around 120 houses and boasted a population of approximately 400 at its peak. Nichols was the third largest of the phosphate mining towns in Bone Valley, compared to the towns of Brewster and Pierce, which boasted a population of 800 and 500 respectively.

In these mining towns, it was not uncommon for multiple families to share a two-story house. Workers rented housing from their employer, which included water, electricity, and rubbish collection. The community had its own general store, hospital, and school. Nichols also had its own church and post office, both of which remain open to this day, though the population began to significantly dwindle in the mid-twentieth century.

A convergence of factors contributed to declines in company-created mining towns like Nichols. 

Nichols Phosphate Mine

Photo of the Nichols Mine circa 1910 that shows wet bin where rail cars bring in the wet phosphate | State Library and Archives of Florida

As automobile ownership became more common and the quality of roads improved, living close to work became less of a priority. People began to move to larger cities nearby for better opportunities for themselves and their families. Mobil Mining and Mineral Company, a subsidiary of Mobil Oil, purchased three mines across the Bone Valley region, including the Nichols mine. In 1960, the remaining company homes were sold to employees and the town of Nichols became an unincorporated community, though operations at the processing plant nearby continued.

Nichols Phosphate Mine

Nichols Phosphate Mine | Photo © 2018 Sugarbomb​

Phosphate ore is found 15 to 50 feet below ground in a mixture of sand, clay, and phosphate rock known as the matrix. Large cranes with buckets scoop up the matrix and deposit it into a pit where high pressure water guns create a slurry, which is then pumped to a beneficiation plant.

At the beneficiation plant, sand and clay are separated from the phosphate rock, which then travels by truck or rail to a fertilizer processing plant. Phosphate rock must be chemically processed before it can be used as a water-soluble fertilizer. At the processing plant, phosphate rock is mixed with sulfuric acid to create the phosphoric acid needed to make fertilizer. The chief end product is diammonium phosphate, which is made by reacting ammonia with phosphoric acid. Phosphorus is quickly depleted in soils and must be replenished regularly as it is critical for root and flower development in all plants. There is no natural or synthetic substitute for phosphate.

Nichols Phosphate Mine

One of the offices at the Nichols Phosphate Mine | Photo © 2018 Sugarbomb​

The demand for phosphate peaked in the mid-1980s. By 1985, over 14,000 people were employed mining and processing phosphate across Bone Valley. In the latter part of the 1980s, the demand for American-mined phosphate would begin to decrease. Foreign countries were investing heavily in mining production and their own processing plants, leading to a sharp decline in the need to import phosphate from the United States and rendering many of the processing plants in Bone Valley obsolete. Nichols temporarily suspended operations in 1986. By 1988, phosphate companies in Bone Valley began experiencing layoffs and temporary closures. Companies continued to struggle through the 1990s as foreign production increased and the price of fertilizer decreased rapidly, ultimately selling off their properties or simply closing completely.

Nichols Phosphate Mine

In 1996, the Nichols mine was purchased by Agrifos Mining LLC, a privately owned fertilizer development company. This sale included approximately 10,000 acres of phosphate reserves, along with the associated facilities and equipment. In a joint partnership with IMC Global, owner of other phosphate mines in the region, IMC operated a fertilizer plant on the property.


IMC would permanently close one of its mines the next year, followed by the closure of three others, also located in Bone Valley, and the Nichols fertilizer plant at the end of 1998. In August 2000, economic conditions caused Agrifos to shutter its Nichols mine, resulting in the loss of 120 jobs. When it closed, the mine in Nichols was one of the smallest phosphate mines in Florida, producing 1.1 metric tons per year.

Since closing, the property has fallen into disrepair. Vandals and thieves have caused an estimated $3 million in damages to the abandoned plant. The Nichols mine is currently private property and trespassing is forbidden. There are no current plans for the location.

Agrifos offices at the Nichols Phosphate Mine | Photo © 2018 Sugarbomb​

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