The horizontal mixer is the most widely used general-purpose mixing equipment in the fertilizer industry. It features a U-shaped or cylindrical horizontal vessel equipped with an internal rotor—typically utilizing either double-layer helical ribbons or mixing paddles. Once materials enter the vessel, the rotating rotor drives them to circulate both axially and radially: the inner ribbon pushes material from the center toward the ends, while the outer ribbon pushes it back from the ends to the center, creating a large-scale convective circulation. These mixers are highly adaptable to materials ranging from powders and granules to high-viscosity pastes, offering rapid mixing speeds, high uniformity, and minimal residual buildup; they are widely used for blending raw materials for both organic and NPK compound fertilizers. Key advantages include immunity to variations in particle size and density, effectiveness with sticky materials, and a gentle mixing process that minimizes damage to fragile granules.

In the field of blended fertilizer (BB fertilizer) production, NPK blenders and BB fertilizer production lines employ a distinct mixing logic. BB fertilizer raw materials consist of pre-granulated single-nutrient fertilizers (such as large-granule urea, monoammonium phosphate, and potassium chloride); the process requires uniform blending without compromising the integrity of the original granules. NPK blenders utilize a specialized internal helical mechanism and a unique three-dimensional structure to ensure a gentle mixing process and smooth discharge, effectively preserving the original state of the materials. A BB (Bulk Blend) fertilizer blending production line typically consists of a computer control system, an automatic batching system, a BB fertilizer mixer, a finished product silo, and an automatic packaging machine. The overall process flow involves the simultaneous automatic batching of various raw materials, conveyance to the mixer for blending, automatic packaging via a scale, bag stitching, and final product discharge. The BB fertilizer mixer is specifically designed to mitigate the issues of stratification and segregation that can occur when mixing granules of varying densities and sizes; it promotes "convection plus diffusion" movement, avoids violent impact and shearing forces, and maximizes the preservation of granule integrity while preventing dust generation and nutrient loss.

In the field of organic fertilizer production, the twin-shaft organic fertilizer mixer represents a high-intensity mixing technology. This equipment utilizes two parallel mixing shafts equipped with helical blades or paddles, rotating synchronously in opposite directions. Subjected to shearing, compression, and convective forces from both directions, the materials undergo mixing at an intensity significantly higher than that of single-shaft equipment. Compared to single-shaft mixing, the twin-shaft method yields a more uniform mixture while offering shorter processing times and higher efficiency. Twin-shaft mixers are particularly well-suited for processing organic materials with high fiber content and high viscosity; the inner walls of the mixing trough are typically lined with a smooth, corrosion-resistant layer to effectively prevent material adhesion and extend the equipment's service life. For the production of bio-organic fertilizers, the twin-shaft mixer enables uniform blending at lower temperatures, thereby avoiding the temperature rise associated with excessive agitation that could otherwise compromise the activity of functional microorganisms.