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Focus On High-Quality Silicate (Ceramic) Materials
STPP Replacement for Ceramic Body Slurry: A Practical Factory Trial Guide
By Goway Chemical Technical Team | Updated July 2026 | Ceramic Body Slip Preparation
Key Takeaways
- Cost reduction of 60–70% on deflocculant procurement. FG-series products are priced at approximately 30–40% of STPP cost while achieving 100% replacement at 0.2–0.5% dosage. (Source: Goway product page, /products_detail/6.html)
- Four FG grades for four process needs. FG-2017 (NaO 30–32%, fast dispersion), FG-MK03 (SiO₂ 20–22%, long-term stability), FG-N203B (SiO₂ 30–33%, spray-drying optimised), FG-SL01A (NaO/SiO₂ balanced 18–20%, universal). (Source: Goway TDS)
- A structured trial takes 2–4 weeks. Four phases: baseline (Days 1–3), lab dosage curve (Days 1–3), pilot batch (Days 4–7), production transition (Days 8–28). Rushing the trial risks viscosity instability and fired body defects.
- Key metrics to monitor: Ford Cup flow time, solid content, 24-hour viscosity drift, spray dryer powder bulk density, green body MOR, fired shrinkage, fired whiteness, and fired breaking modulus.
- FG-ZM01 body binder is complementary. When used alongside FG-series deflocculants, FG-ZM01 can reduce total deflocculant demand while increasing green strength by 30–70%. (Source: Goway TDS, FG-ZM01)
§1 Why Replace STPP? Five Drivers and the FG-Series Alternative
Sodium tripolyphosphate (STPP) has been the workhorse deflocculant for ceramic body slurry for decades. However, five practical drivers are pushing tile, sanitaryware, and porcelain manufacturers to evaluate alternatives. Understanding these drivers helps define your success criteria before starting a trial.
The Five Replacement Drivers
| # | Driver | What Happens with STPP | How FG-Series Addresses It |
|---|---|---|---|
| 1 | Cost pressure | STPP prices have risen with phosphate rock scarcity and environmental mining controls. Typical ceramic-grade STPP (Na₅P₃O₁₀ 94% min) commands a premium over silicate-based alternatives. | FG-series products are priced at 30–40% of STPP cost. At equivalent or slightly lower dosage, this yields 60–70% direct material savings. (Source: Goway product page) |
| 2 | Water quality variability | STPP is highly sensitive to Ca²⁺ and Mg²⁺ in process water. Hardness above ~80–100 mg/L causes STPP to react preferentially with calcium, reducing deflocculation efficiency and requiring overdosing. (Industry-typical reference) | FG-MK03 (SiO₂ 20–22%) and FG-SL01A (SiO₂ 18–20%) provide silicate-mediated stabilisation that buffers against moderate ionic contamination. (Source: Goway TDS, FG-MK03 / FG-SL01A) |
| 3 | Environmental compliance | STPP contributes phosphorus to wastewater. Phosphorus discharge limits are tightening in many ceramics production regions. P₂O₅ from STPP (56% content) can push effluent TP above permit thresholds. | FG-2017 and FG-N203B contain only 0–1% P₂O₅ — drastically reducing phosphorus discharge compared to STPP's 56% P₂O₅. (Source: Goway TDS) |
| 4 | Solid content improvement | STPP's narrow deflocculation plateau can limit achievable solid content, especially with variable raw materials. Lower solid content means more water to evaporate in the spray dryer — the single largest energy consumer in body preparation. | FG-N203B (SiO₂ 30–33%, L.O.I 45–50%) is engineered for high-solid spray-drying slurries, providing viscosity buffering at elevated solid content. (Source: Goway TDS, FG-N203B) |
| 5 | Slurry stability over time | STPP-based slurries can experience viscosity creep after 12–24 hours of storage, particularly when raw material batches vary. This creates scheduling pressure and quality inconsistency. | FG-MK03 is designed for long-term viscosity stability in stored slurry (12–48 hours), making it ideal for shift-change and weekend storage scenarios. (Source: Goway TDS, FG-MK03) |
| Water hardness thresholds and viscosity creep behaviour are industry-typical reference values. Actual performance depends on your clay mineralogy, water chemistry, and body formulation. Goway product data is cited from Goway Technical Data Sheet. | |||
STPP vs. FG-Series: Quick Comparison
| Parameter | STPP (FG-1003) | FG-Series (FG-2017 / MK03 / N203B / SL01A) |
|---|---|---|
| Active chemistry | Na₅P₃O₁₀ 94% min; P₂O₅ 56% (Source: Goway TDS, FG-1003) | NaO + SiO₂ + P₂O₅ in varying ratios (Source: Goway TDS) |
| Indicative price vs. STPP | 100% (baseline) | 30–40% of STPP price (Source: Goway product page) |
| Recommended dosage | 0.3–0.5% on dry body weight (industry-typical) | 0.2–0.5% on dry body weight (Source: Goway TDS) |
| P₂O₅ content | 56% — high phosphorus load | 0–2% — minimal phosphorus load |
| Appearance | White powder | Yellowish/white granular (Source: Goway product page) |
| Packaging | 25 kg/bag | 25 kg/bag |
| STPP replacement claim | — | 100% replacement (Source: Goway product page) |
For a broader comparison of organic vs. inorganic deflocculant families — including polycarboxylate (PCE) options and total cost of ownership modelling — see our guide: Organic vs. Inorganic Deflocculants: Cost-Benefit Analysis for Ceramic Slip.
§2 The FG-Series Portfolio: Four Deflocculants, Four Strengths
The FG-series is not a single product but a portfolio of four deflocculants, each engineered around a different NaO:SiO₂ ratio. This ratio determines the balance between pure electrostatic deflocculation (NaO-dominated) and partial steric stabilisation (SiO₂ chain contribution). Selecting the correct grade is the single most important decision in the replacement process.
Chemical Composition Comparison
| Parameter | FG-2017 | FG-MK03 | FG-N203B | FG-SL01A |
|---|---|---|---|---|
| Type | Dispersant | Dispersant | Deflocculant | Deflocculant |
| NaO (%) | 30–32 | 12–15 | 15–18 | 18–20 |
| SiO₂ (%) | — (none) | 20–22 | 30–33 | 18–20 |
| P₂O₅ (%) | 0–1 | 1–2 | 0–1 | 1–2 |
| L.O.I (%) | 55–60 | 55–65 | 45–50 | 55–60 |
| Positioning | Fast dispersion | Long-term stability | Spray-drying optimised | Universal / multi-body |
| Source: Goway Technical Data Sheet (v2.1, 2026-05-14), validated by Goway Product Team. All values are specification ranges; batch-specific COA available on request. | ||||
Product Detail Cards
FG-2017 Fast Dispersion
Highest NaO in the series (30–32%). No SiO₂ content — pure single-electrolyte deflocculation. Na⁺ ions rapidly exchange with Ca²⁺/Mg²⁺ on clay particle edges, eliminating flocculation forces quickly.
- Best for: Wall tile and floor tile body slurry; high-throughput ball mill lines; single-body production
- Mechanism: Electrostatic repulsion via high-concentration Na⁺ ion exchange
- Caution: No SiO₂ buffer — more sensitive to water hardness. If Ca²⁺ exceeds ~50 mg/L, monitor Ford Cup viscosity more frequently or blend with a silicate-containing grade
Source: Goway TDS, FG-2017
FG-MK03 Long-Term Stability
Balanced NaO (12–15%) + significant SiO₂ (20–22%). Silicate anions adsorb on clay particle edges, forming a protective layer that maintains inter-particle repulsion over extended storage periods.
- Best for: Slurry stored 12–48 hours before spray drying or casting; shift-change and weekend storage; high-clay-content bodies; hard water regions
- Mechanism: Combined Na⁺ ion exchange + silicate layer adsorption
- Advantage: Superior tolerance to water hardness variation compared to pure NaO types
Source: Goway TDS, FG-MK03
FG-N203B Spray-Drying Optimised
Highest SiO₂ in the series (30–33%) and lowest L.O.I (45–50%). High silicate concentration creates a more complete protective layer on clay surfaces — especially effective in high-solid systems where particle proximity increases re-flocculation tendency.
- Best for: Spray-drying body lines; high-solid slurry (>60 wt%); large-format porcelain tile; vitrified tile; continuous pump lines
- Mechanism: Primarily silicate layer adsorption with supplementary Na⁺ exchange
- Advantage: Low L.O.I means higher effective active ingredient concentration per unit volume — dosage calculation should be based on dry active ingredient weight, not product volume
Source: Goway TDS, FG-N203B
FG-SL01A Universal / Multi-Body
Symmetrical NaO/SiO₂ ratio (both 18–20%). Three deflocculation mechanisms operate in parallel: Na⁺ ion exchange, silicate layer adsorption, and phosphate complexation (from 1–2% P₂O₅). This unique balance makes it the most versatile grade.
- Best for: Multi-product ceramic factories; combined wall/floor tile lines; sanitaryware casting; mixed clay formulations; factories with variable water quality
- Mechanism: Triple-action: electrostatic + steric + phosphate complexation
- Advantage: Predictable dosage response across different body types — ideal for facilities running multiple formulations
Source: Goway TDS, FG-SL01A
Product Selection Decision Matrix
| Factory Scenario | Recommended Product | Key Parameter Basis | Dosage Starting Point |
|---|---|---|---|
| Wall tile / floor tile body slurry; fast throughput; single body type | FG-2017 | NaO 30–32% — highest in series for rapid dispersion | 0.3% (adjust ±0.05%) |
| Slurry stored 12–48 h before use; weekend storage; hard water | FG-MK03 | SiO₂ 20–22% — silicate layer for long-term stability | 0.35% (adjust ±0.05%) |
| High-solid spray-drying slurry; large-format porcelain tile | FG-N203B | SiO₂ 30–33%, L.O.I 45–50% — densest active ingredient | 0.3% (adjust ±0.05%) |
| Multi-product factory; various body types; variable water quality | FG-SL01A | NaO 18–20% / SiO₂ 18–20% — balanced triple-action | 0.35% (adjust ±0.05%) |
| Hard water (>100 mg/L Ca²⁺) + moderate recycled content | FG-MK03 or FG-SL01A | Silicate buffer against ionic contamination | 0.35–0.4% |
| Phosphorus discharge near regulatory limit | FG-2017 or FG-N203B | P₂O₅ 0–1% — minimal phosphorus contribution | 0.3% (adjust ±0.05%) |
| Dosage starting points are based on Goway TDS recommended range of 0.2–0.5%. Exact optimum must be determined by five-point dosage curve test with your actual body recipe and process water. See §4 for protocol. | |||
§3 Baseline Data Collection: 10 Parameters to Measure First
Before changing any deflocculant, document your current system comprehensively. This baseline is your reference for evaluating whether the switch is successful. If you skip this step, you cannot objectively judge the trial results.
| # | Parameter | How to Measure | Why It Matters |
|---|---|---|---|
| 1 | Ford Cup flow time | Ford Cup #4 at 25°C; measure 3 times per batch, record average | Primary viscosity benchmark — the single most important comparison metric |
| 2 | Slurry solid content | Weigh 100 g slurry, dry at 110°C to constant weight, calculate % | Determines water-to-evaporate in spray dryer; target is to maintain or improve |
| 3 | Current STPP dosage | Record actual addition rate (kg per tonne dry body) over 5 consecutive batches | Baseline for dosage comparison and cost calculation |
| 4 | Process water hardness | EDTA titration or hardness test kit; measure Ca²⁺ and Mg²⁺ separately | Determines which FG grade is most suitable and whether water treatment is needed |
| 5 | Process water pH and conductivity | pH meter and conductivity meter; record daily for 1 week | pH affects deflocculant ionisation; conductivity indicates total ionic load |
| 6 | Slurry pH | pH meter on fresh slurry and 24 h stored slurry | Deflocculant performance is pH-dependent; track drift over storage time |
| 7 | 24-hour viscosity drift | Measure Ford Cup at 0 h, 4 h, 8 h, 24 h after preparation | Key stability metric — large drift indicates inadequate stabilisation |
| 8 | Body recipe (full composition) | Document all components and percentages: kaolin, ball clay, feldspar, quartz, talc, recycled material | Required for lab trial replication and for Goway technical support |
| 9 | Spray dryer parameters | Inlet/outlet temperature, powder moisture, powder bulk density, granule size distribution (40/60/80 mesh) | Defines powder quality baseline for before/after comparison |
| 10 | Green and fired body properties | Green MOR (modulus of rupture), fired shrinkage, fired whiteness, fired MOR, warpage | Ultimate quality validation — ensures the switch does not compromise end-product quality |
Success Criteria Template
Define your success criteria before starting the trial. Use this template:
Replace bracketed values with your factory-specific targets. Without defined criteria, trial results are subjective and difficult to interpret. For guidance on viscosity measurement methodology, see our guide on water quality and ceramic slip performance.
§4 Lab Trial: Five-Point Dosage Curve Protocol
The five-point dosage curve is the cornerstone of the entire replacement process. It identifies the minimum-viscosity plateau for each FG grade using your actual body recipe and process water, enabling data-driven product selection and dosage optimisation.
-
Prepare Representative Slip Samples
Use your actual body recipe (full mineral mix, not just clay fraction) at your target solid content (±0.5%). Use process water from your factory — not distilled water. The ionic composition of process water is a critical variable that affects deflocculant performance. Prepare 1 kg lab batches for each dosage point.
-
Define Five Dosage Points
For each FG grade under evaluation, prepare five samples at evenly-spaced dosage points spanning the expected plateau. Based on Goway's recommended range of 0.2–0.5% (Source: Goway TDS), a typical five-point set is:
Point Dosage (% dry body weight) Purpose 1 0.15% Below expected plateau — under-dosed 2 0.25% Approaching plateau 3 0.35% Expected optimum 4 0.45% Above expected plateau 5 0.55% Over-dosed — confirms plateau ceiling For FG-N203B, which has lower L.O.I (45–50%) and higher active ingredient density, consider starting at 0.10% and using 0.10% increments. Dosage calculation should be based on dry active ingredient weight, not product volume.
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Prepare Samples Consistently
Add deflocculant after body minerals are fully dispersed in water. Stir at consistent speed and duration for all samples. Allow 30 minutes equilibration before first measurement. Record slurry temperature — it should be within ±2°C across all samples.
-
Measure Ford Cup #4 Flow Time
Record Ford Cup #4 flow time at 25°C for each dosage point at three time intervals: 30 minutes, 2 hours, and 24 hours after preparation. If available, also use a Brookfield viscometer (spindle #3, 20 rpm and 100 rpm) to calculate the Thixotropy Index = viscosity at 20 rpm / viscosity at 100 rpm. Target TI for body slip: typically 1.2–1.8 (industry-typical reference).
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Plot the Dosage-Viscosity Curve
Plot dosage (x-axis) against Ford Cup flow time (y-axis) for each time interval. The curve typically shows: (a) high viscosity at low dosage (under-deflocculated), (b) a steep drop as dosage increases, (c) a minimum-viscosity plateau where additional dosage produces little improvement, and (d) a potential viscosity rise at over-dosage (deflocculation reversal). The target operating point is the middle of the plateau, not its low-viscosity edge — this provides maximum tolerance to raw material and water quality variation.
-
Compare FG Grades and Select
Run the five-point curve for 2–3 FG grades that match your process scenario (see §2 decision matrix). Compare: (a) plateau minimum viscosity, (b) plateau width (dosage tolerance band), (c) 24-hour viscosity drift, and (d) behaviour at over-dosage. Select the grade with the widest plateau and lowest 24-hour drift at your target viscosity. For a deeper understanding of the electrostatic mechanisms behind these curves, see our beginner's guide to zeta potential in ceramic slurries.
Dosage Curve Interpretation Guide
| Curve Shape | What It Means | Recommended Action |
|---|---|---|
| Wide, flat plateau (low viscosity maintained across 3+ dosage points) | Ideal — the product is well-matched to your body formula and water. Good tolerance to variation. | Operate at the middle of the plateau. Proceed to pilot trial. |
| Narrow plateau (viscosity minimum at only 1–2 dosage points) | The product works but has limited tolerance. Small material or water variations may push you off the optimum. | Try a different FG grade (higher SiO₂ typically widens the plateau) or consider blending two grades. |
| No clear plateau (viscosity decreases monotonically with dosage) | Under-dosed across the entire range, or the product is not compatible with your body mineralogy. | Extend the dosage range upward (add 0.65% and 0.75% points). If still no plateau, try a different FG grade. |
| Viscosity rises at high dosage (U-shaped or J-shaped curve) | Over-deflocculation — excess electrolyte compresses the double layer and re-flocculates the slurry. | This is normal and confirms the upper boundary. Operate well below the reversal point. |
| Large 24 h drift at all dosage points | Slurry is not adequately stabilised for storage. May indicate water quality issue or clay mineralogy mismatch. | Check water hardness. Try FG-MK03 (designed for long-term stability). Consider water softening if hardness is high. |
§5 Pilot Trial: 200–500 kg Batch Validation
The lab dosage curve identifies the optimal product and dosage. The pilot trial validates that this translates to production-scale performance — where factors like mill heat generation, scale-dependent mixing efficiency, and spray dryer dynamics come into play.
-
Prepare a 200–500 kg Pilot Batch
Use the lab-optimised dosage (middle of plateau) and your standard production body recipe. Charge the ball mill with actual production raw materials and process water. Add the selected FG-grade deflocculant at the lab-determined dosage. Record all addition quantities and times.
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Monitor Viscosity at Production Scale
Measure Ford Cup flow time at 0 h, 4 h, 8 h, and 24 h after mill discharge. Compare to your baseline (§3). Acceptable criteria: flow time within ±5 seconds of baseline at 0 h, and ≤15% increase at 24 h. If viscosity is significantly higher than lab results, investigate temperature differences (production mill runs hotter) and scale effects.
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Measure Solid Content
Verify that solid content is maintained at or above baseline. If the FG-series deflocculant allows higher solid content at the same viscosity, record this — it is a direct spray dryer energy saving opportunity. Even a 1–2 percentage point improvement in solid content generates meaningful energy savings at production scale. (Industry-typical reference — validate with your spray dryer energy data.)
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Spray-Dry the Pilot Batch
Run the pilot slurry through your spray dryer. Monitor: inlet temperature, outlet temperature, powder moisture content, powder bulk density, and granule size distribution (40 mesh / 60 mesh / 80 mesh fractions). Compare all parameters to baseline. Pay special attention to powder bulk density — a significant decrease may indicate higher hollow granule rate, which affects pressing quality.
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Press Test Tiles and Measure Green Body
Press standard test tiles from the spray-dried powder. Measure: green density, green MOR (modulus of rupture), dimensional consistency, and surface visual quality. Compare to baseline. Note any changes in pressing behaviour (required pressure, ejection force, cycle time). If green strength is below target, consider adding FG-ZM01 ceramic body binder at 0.15–0.3% — it increases green strength by 30–70% while improving slurry flow. (Source: Goway TDS, FG-ZM01)
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Go/No-Go Decision
Compare all pilot results against your success criteria (§3). The Go/No-Go decision framework:
Parameter Go (Proceed to Production) No-Go (Investigate) Ford Cup flow time Within ±5 s of baseline > ±10 s deviation 24 h viscosity drift ≤ 15% increase > 25% increase Solid content ≥ baseline Below baseline by >1% Spray dryer powder quality Bulk density within ±5% >10% decrease Green body MOR Within ±10% of baseline >15% decrease Visual quality No new defects New lamination, pinholes, or cracking
§6 Full-Scale Production Transition
Once the pilot trial is validated, the full-scale transition follows a phased approach. The goal is to introduce the new deflocculant without disrupting ongoing production — this means gradual changeover with continuous monitoring.
Four-Phase Transition Timeline
| Phase | Timeline | Activity | Key Deliverable |
|---|---|---|---|
| Phase 1: Parallel preparation | Days 1–3 | Prepare the first full production batch with FG-series deflocculant. Run parallel to existing STPP-based production if possible, or transition one mill line at a time. | Full-scale viscosity and solid content confirmation |
| Phase 2: Stability monitoring | Days 4–7 | Monitor Ford Cup flow time, solid content, and 24 h drift for 3–5 consecutive production days. Record all data. Watch for any excursions requiring operator intervention. | 5-day stability data set |
| Phase 3: Fired body validation | Days 8–14 | Fire tiles from the FG-series production batch through standard kiln cycle. Measure fired shrinkage, warpage, whiteness, and MOR. Compare to baseline. | Fired body quality sign-off |
| Phase 4: SOP update and rollout | Days 15–28 | Update standard operating procedures: new target dosage (with ±tolerance), Ford Cup target range, water hardness monitoring frequency, corrective action triggers. Train operators on new parameters. | Updated SOP and operator training completion |
Three Transition Strategies
| Strategy | Description | Best For | Risk Level |
|---|---|---|---|
| A. Direct switch | Stop STPP completely; introduce FG-series at lab-optimised dosage from Day 1. | Single-body factories with consistent raw materials and clean water; strong lab and pilot results | Medium — fastest but least forgiving |
| B. Phased introduction | Reduce STPP dosage by 50% and introduce FG-series at 50% of target dosage. Gradually increase FG-series while decreasing STPP over 2–3 mill cycles. | Continuous milling operations; factories with variable raw materials | Low — safest approach for live production |
| C. Blend transition | Run FG-series and STPP simultaneously at reduced dosages for 1 week, then eliminate STPP. | Factories with limited lab capacity; risk-averse operations | Lowest — but extends transition period |
| Strategy B (phased introduction) is recommended for most factories. It provides a safety margin during the transition and allows operators to become familiar with the new deflocculant's behaviour before full commitment. | |||
Production Monitoring Parameters
| Parameter | Monitoring Frequency | Target Range | Corrective Action if Out of Range |
|---|---|---|---|
| Ford Cup flow time | Every batch (or every 4 h) | ±5 s of target | Adjust dosage by ±0.02%; re-check after 30 min |
| Slurry solid content | Every 8 h | ±0.5% of target | Adjust water addition; check deflocculant dosage |
| 24 h viscosity drift | Daily | ≤ 15% increase from 0 h | If >20%, switch to FG-MK03 or investigate water quality change |
| Slurry temperature | Every 4 h | 25–35°C (production environment) | If >40°C, increase mill cooling; high temp affects deflocculant performance |
| Process water hardness | Weekly (or daily if variable source) | Document baseline; track variation | If hardness increases >20%, increase dosage slightly or switch to higher-SiO₂ grade |
| Spray dryer powder bulk density | Every 4 h | ±5% of baseline | Check granule size distribution; adjust atomisation pressure if needed |
| Green body MOR | Daily (5 samples) | ≥ baseline | If <90% of baseline, add FG-ZM01 binder at 0.15% (Source: Goway TDS, FG-ZM01) |
| Fired tile whiteness | Each kiln cycle | ±1.0 L* of baseline | If whiteness drops, check Fe₂O₃ in raw materials; consider kaolin grade adjustment |
| These monitoring parameters should be maintained for at least 4 weeks after the transition is complete, then reduced to routine frequency once stability is confirmed. | |||
§7 Before/After Metrics and Cost Savings Calculation
The ultimate validation of the STPP replacement is a side-by-side comparison of key performance and cost metrics. Use this framework to quantify the improvement and present results to management.
12-Metric Before/After Comparison Table
| Metric | Before (STPP) | After (FG-Series) | Assessment |
|---|---|---|---|
| 1. Deflocculant type | STPP (FG-1003) | [FG-grade selected] | — |
| 2. Dosage (% dry body) | [baseline]% | [trial]% | Target: ≤ baseline |
| 3. Ford Cup flow time (s) | [baseline] s | [trial] s | Target: ±5 s |
| 4. Solid content (%) | [baseline]% | [trial]% | Target: ≥ baseline |
| 5. 24 h viscosity drift (%) | [baseline]% | [trial]% | Target: ≤ baseline |
| 6. Deflocculant cost (CNY/kg) | [STPP price] | [FG price] | Target: 30–40% of STPP (Source: Goway product page) |
| 7. Cost per tonne slip (CNY) | [calculated] | [calculated] | Target: 60–70% reduction |
| 8. Spray dryer powder bulk density | [baseline] | [trial] | Target: ±5% |
| 9. Green body MOR (MPa) | [baseline] | [trial] | Target: ≥ baseline |
| 10. Fired shrinkage (%) | [baseline]% | [trial]% | Target: ±0.2% |
| 11. Fired whiteness (L*) | [baseline] | [trial] | Target: ±1.0 |
| 12. Fired MOR (MPa) | [baseline] | [trial] | Target: ±5% |
| Replace bracketed values with your measured data. Metrics 6–7 are the primary cost justification; metrics 3–5 and 8–12 are the primary quality validation. | |||
Annual Cost Savings Calculation
Cost Savings Formula
The 30–40% price ratio of FG-series vs. STPP is a Goway product page claim. Actual prices require a formal quotation. All indirect savings are plant-specific and must be measured, not assumed.
If solid content improved by 1–2 percentage points during the trial, calculate the spray dryer energy saving separately. For every 1% increase in solid content, approximately 1.5–2% less water needs to be evaporated — at production scale, this can be a six-figure annual energy saving. (Industry-typical reference — actual savings depend on spray dryer specifications and energy costs.) For spray dryer optimization methodology, see our guide on maximizing spray dryer output and granule morphology.
§8 Troubleshooting Guide
Even with careful trial work, production-scale transitions can encounter issues. These troubleshooting cards address the most common problems observed during STPP-to-FG-series replacement.
Problem: Viscosity higher than lab results at production scale
Likely cause: Temperature difference — production ball mills generate more heat than lab equipment, and slurry temperature affects deflocculant performance. Also check whether the lab water sample was representative of production water across the full day.
Suggested action: (a) Measure production slurry temperature at discharge; if >35°C, re-run lab trials at production temperature; (b) Increase FG-series dosage by 0.02–0.05% and re-test; (c) Verify that process water hardness on the production day matches the lab sample.
Problem: 24-hour viscosity drift exceeds 20%
Likely cause: The selected FG grade does not provide sufficient long-term stabilisation for your slurry storage conditions. This is common with FG-2017 (no SiO₂ buffer) in bodies with variable clay mineralogy.
Suggested action: (a) Switch to FG-MK03 (SiO₂ 20–22%, designed for long-term stability); (b) If already using FG-MK03, increase dosage by 0.05%; (c) Check whether water hardness has changed — a new water source or seasonal variation can destabilise the system.
Problem: Fired body whiteness decreased slightly
Likely cause: STPP's phosphate (P₂O₅ 56%) acts as a mild flux and can contribute to glass phase whiteness. FG-series products with lower P₂O₅ (0–2%) may slightly alter the fired body mineralogy. This is a compositional change, not a quality defect.
Suggested action: (a) Check if the whiteness change is within your commercial tolerance (±1.0 L*); (b) If outside tolerance, adjust firing temperature by ±5–10°C to compensate for flux change; (c) Review kaolin grade — switching to a higher-whiteness kaolin such as FG-K90 (whiteness 90.0) can offset the difference. (Source: Goway TDS, FG-K90)
Problem: Green body strength decreased after switch
Likely cause: STPP's sodium content can slightly enhance green body binding through sodium-clay interactions. Removing it may marginally reduce green strength, particularly in bodies with low-plasticity clays or high barren material content.
Suggested action: (a) Add FG-ZM01 ceramic body binder at 0.15–0.3% — this increases green strength by 30–70% while improving slurry flow by 5–10 seconds Ford Cup. (Source: Goway TDS, FG-ZM01); (b) Alternatively, increase ball clay content (e.g., FG-B82 high-plasticity ball clay) by 2–3%.
Problem: Spray dryer powder bulk density decreased
Likely cause: Slurry rheology change affects atomisation behaviour, which can increase the hollow granule rate. This is more common when switching to a deflocculant with significantly different viscosity characteristics at the same solid content.
Suggested action: (a) Check granule size distribution — if the over-fine fraction (<40 mesh) increased, increase atomisation pressure slightly; (b) If solid content can be raised by 1–2% with the new deflocculant, this typically improves granule density; (c) Consider adding FG-ZM01 binder, which has been shown to improve granule size distribution and reduce hollow granule rate. (Source: Goway TDS, FG-ZM01)
Problem: Viscosity excursions on specific production days
Likely cause: Raw material batch variation — different clay deliveries can have varying mineralogy, Fe₂O₃ content, and organic matter. The FG-series may be more or less sensitive to these variations than STPP, depending on the grade selected.
Suggested action: (a) Track which raw material delivery corresponds to viscosity excursions; (b) Tighten incoming QC on kaolin and ball clay (monitor Fe₂O₃, K₂O, and L.O.I variation); (c) If excursions correlate with high-K₂O batches, switch to FG-SL01A (triple-action mechanism, more tolerant of mineralogy variation). For a comprehensive additive troubleshooting framework, see our guide to troubleshooting common ceramic additive problems.
§9 Frequently Asked Questions
Yes. Goway FG-series deflocculants (FG-2017, FG-MK03, FG-N203B, FG-SL01A) are engineered as 100% STPP replacements for ceramic body slurry. At 0.2–0.5% dosage on dry body weight, they achieve equivalent or better deflocculation performance compared to STPP at typical 0.3–0.5% dosage. The key is selecting the correct FG grade for your specific process conditions: FG-2017 for fast dispersion, FG-MK03 for long-term slurry stability, FG-N203B for high-solid spray-drying slurries, and FG-SL01A for multi-body universal applications. A structured lab-to-production trial is recommended before full-scale adoption.
Goway FG-series deflocculants are priced at approximately 30–40% of STPP cost, while achieving 100% replacement at similar or slightly lower dosage (0.2–0.5% vs. STPP 0.3–0.5% on dry body weight). On a direct material cost basis, this typically yields 60–70% savings on deflocculant procurement. Additional indirect savings may come from improved slurry stability reducing scrap, and in some cases from achievable higher solid content reducing spray dryer energy consumption. Actual savings depend on your current STPP price, dosage, body formulation, and process conditions.
A structured trial typically takes 2–4 weeks across four phases. Phase 1 (Days 1–3): baseline data collection and lab five-point dosage curve. Phase 2 (Days 4–7): pilot trial with 200–500 kg batch, measuring flow time, solid content, spray drying parameters, and green body properties. Phase 3 (Days 8–14): full production trial run with 3–5 day viscosity stability monitoring. Phase 4 (Days 15–28): fired body evaluation including shrinkage, warpage, whiteness, and breaking modulus. The timeline depends on kiln cycle time and the number of parameters requiring comparison.
Product selection depends on your primary process challenge. For wall tile and floor tile body slurry needing fast dispersion: FG-2017 (NaO 30–32%, highest in the series). For slurry stored 12–48 hours before use or hard water conditions: FG-MK03 (SiO₂ 20–22%, provides long-term viscosity stability). For high-solid spray-drying slurry or large-format porcelain tile: FG-N203B (SiO₂ 30–33%, highest in the series, lowest L.O.I at 45–50%). For multi-product factories with various body types: FG-SL01A (balanced NaO 18–20% / SiO₂ 18–20%). A lab dosage curve test with your actual body recipe is the definitive selection method.
FG-series deflocculants are inorganic products that leave mineral residues in the fired body, similar to STPP. The key difference is the NaO:SiO₂ ratio: STPP contributes phosphate (P₂O₅ 56%) which acts as a flux, while FG-series products contribute varying ratios of sodium oxide and silicate. In most standard tile body formulations, the fired body impact is minimal and may actually improve surface quality. However, the glass phase composition changes slightly, so a fired body evaluation (shrinkage, warpage, colour, MOR) is mandatory before full-scale adoption. FG-series products with low P₂O₅ (0–1%) also reduce the phosphorus load on the fired body compared to STPP.
Yes. FG-series deflocculants and FG-ZM01 body binder are complementary products. FG-ZM01 is an organic polymer binder that increases green strength by 30–70% at 0.15–0.3% dosage while simultaneously improving slurry flow (Ford Cup flow time improves by 5–10 seconds). Because FG-ZM01 improves flow independently, it can reduce the deflocculant dosage required, creating a combined cost saving. When using both together, Goway recommends evaluating each additive independently first, then conducting a joint usage trial to confirm compatibility and optimal combined dosage.
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View FG-Series Ceramic Deflocculant Products →To submit an inquiry, visit our Ceramic Deflocculant product page and use the inquiry form. Please reference this guide when submitting. Samples with TDS, SDS, and COA are available.
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